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Anke Becker - One of the best experts on this subject based on the ideXlab platform.
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Stable inheritance of Sinorhizobium meliloti cell growth polarity requires an FtsN-like protein and an amidase.
Nature communications, 2021Co-Authors: Elizaveta Krol, Lisa Stuckenschneider, Joana M. Kästle Silva, Peter L. Graumann, Anke BeckerAbstract:In Rhizobiales bacteria, such as Sinorhizobium meliloti, cell elongation takes place only at new cell poles, generated by cell division. Here, we show that the role of the FtsN-like protein RgsS in S. meliloti extends beyond cell division. RgsS contains a conserved SPOR domain known to bind amidase-processed peptidoglycan. This part of RgsS and peptidoglycan amidase AmiC are crucial for reliable selection of the new cell pole as cell elongation zone. Absence of these components increases mobility of RgsS molecules, as well as abnormal RgsS accumulation and positioning of the growth zone at the old cell pole in about one third of the cells. These cells with inverted growth polarity are able to complete the cell cycle but show partially impaired chromosome segregation. We propose that amidase-processed peptidoglycan provides a landmark for RgsS to generate cell polarity in unipolarly growing Rhizobiales. In Sinorhizobium bacteria, cell elongation takes place only at new cell poles, generated by cell division. Here, Krol et al. show that an FtsN-like protein and a peptidoglycan amidase are crucial for reliable selection of the new cell pole as cell elongation zone.
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Tol-Pal System and Rgs Proteins Interact to Promote Unipolar Growth and Cell Division in Sinorhizobium meliloti
mBio, 2020Co-Authors: Elizaveta Krol, Hamish C. L. Yau, Marcus Lechner, Simon Schäper, Gert Bange, Waldemar Vollmer, Anke BeckerAbstract:Sinorhizobium meliloti is an alphaproteobacterium belonging to the Rhizobiales Bacteria from this order elongate their cell wall at the new cell pole, generated by cell division. Screening for protein interaction partners of the previously characterized polar growth factors RgsP and RgsM, we identified the inner membrane components of the Tol-Pal system (TolQ and TolR) and novel Rgs (rhizobial growth and septation) proteins with unknown functions. TolQ, Pal, and all Rgs proteins, except for RgsE, were indispensable for S. meliloti cell growth. Six of the Rgs proteins, TolQ, and Pal localized to the growing cell pole in the cell elongation phase and to the septum in predivisional cells, and three Rgs proteins localized to the growing cell pole only. The putative FtsN-like protein RgsS contains a conserved SPOR domain and is indispensable at the early stages of cell division. The components of the Tol-Pal system were required at the late stages of cell division. RgsE, a homolog of the Agrobacterium tumefaciens growth pole ring protein GPR, has an important role in maintaining the normal growth rate and rod cell shape. RgsD is a periplasmic protein with the ability to bind peptidoglycan. Analysis of the phylogenetic distribution of the Rgs proteins showed that they are conserved in Rhizobiales and mostly absent from other alphaproteobacterial orders, suggesting a conserved role of these proteins in polar growth.IMPORTANCE Bacterial cell proliferation involves cell growth and septum formation followed by cell division. For cell growth, bacteria have evolved different complex mechanisms. The most prevalent growth mode of rod-shaped bacteria is cell elongation by incorporating new peptidoglycans in a dispersed manner along the sidewall. A small share of rod-shaped bacteria, including the alphaproteobacterial Rhizobiales, grow unipolarly. Here, we identified and initially characterized a set of Rgs (rhizobial growth and septation) proteins, which are involved in cell division and unipolar growth of Sinorhizobium meliloti and highly conserved in Rhizobiales Our data expand the knowledge of components of the polarly localized machinery driving cell wall growth and suggest a complex of Rgs proteins with components of the divisome, differing in composition between the polar cell elongation zone and the septum.
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Tol-Pal system and Rgs proteins interact to promote unipolar growth and cell division in Sinorhizobium meliloti
2020Co-Authors: Elizaveta Krol, Hamish C. L. Yau, Marcus Lechner, Simon Schäper, Gert Bange, Waldemar Vollmer, Anke BeckerAbstract:Sinorhizobium meliloti is an α-proteobacterium belonging to the Rhizobiales. Bacteria from this order elongate their cell wall at the new cell pole, generated by cell division. Screening for protein interaction partners of the previously characterized polar growth factors RgsP and RgsM, we identified the inner membrane components of the Tol-Pal system (TolQ and TolR) and novel Rgs (rhizobial growth and septation) proteins with unknown functions. TolQ, Pal and all Rgs proteins, except for RgsE, were indispensable for S. meliloti cell growth. Six of the Rgs proteins, TolQ and Pal localized to the growing cell pole in the cell elongation phase and to the septum in pre-divisional cells, and three Rgs proteins localized to growing cell pole only. The FtsN-like protein RgsS contains a conserved SPOR domain and is indispensable at the early stages of cell division. The components of the Tol-Pal system were required at the late stages of cell division. RgsE, a homolog of the Agrobacterium tumefaciens growth pole ring protein GPR, has an important role in maintaining the normal growth rate and rod cell shape. RgsD is a novel periplasmic protein with the ability to bind peptidoglycan. Analysis of the phylogenetic distribution of novel Rgs proteins showed that they are conserved in Rhizobiales and mostly absent from other α-proteobacterial orders, suggesting a conserved role of these proteins in polar growth.
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Seven-transmembrane receptor protein RgsP and cell wall-binding protein RgsM promote unipolar growth in Rhizobiales.
PLOS Genetics, 2018Co-Authors: Simon Schäper, Elizaveta Krol, Hamish C. L. Yau, Waldemar Vollmer, Dorota Skotnicka, Thomas Heimerl, Joe Gray, Volkhard Kaever, Lotte Søgaard-andersen, Anke BeckerAbstract:Members of the Rhizobiales (class of α-proteobacteria) display zonal peptidoglycan cell wall growth at one cell pole, contrasting with the dispersed mode of cell wall growth along the sidewalls of many other rod-shaped bacteria. Here, we show that the seven-transmembrane receptor (7TMR) protein RgsP (SMc00074), together with the putative membrane-anchored peptidoglycan metallopeptidase RgsM (SMc02432), have key roles in unipolar peptidoglycan formation during growth and at mid-cell during cell division in Sinorhizobium meliloti. RgsP is composed of a periplasmic globular 7TMR-DISMED2 domain, a membrane-spanning region, and cytoplasmic PAS, GGDEF and EAL domains. The EAL domain confers phosphodiesterase activity towards the second messenger cyclic di-GMP, a key regulatory player in the transition between bacterial lifestyles. RgsP and RgsM localize to sites of zonal cell wall synthesis at the new cell pole and cell divison site, suggesting a role in cell wall biogenesis. The two proteins are essential for cell wall biogenesis and cell growth. Cells depleted of RgsP or RgsM had an altered muropeptide composition and RgsM binds to peptidoglycan. RgsP and RgsM orthologs are functional when interchanged between α-rhizobial species pointing to a conserved mechanism for cell wall biogenesis/remodeling within the Rhizobiales. Overall, our findings suggest that RgsP and RgsM contribute to the regulation of unipolar cell wall biogenesis in α-rhizobia.
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Conservation and Occurrence of Trans-Encoded sRNAs in the Rhizobiales
Genes, 2011Co-Authors: Jan Reinkensmeier, Jan-philip Schlüter, Robert Giegerich, Anke BeckerAbstract:Post-transcriptional regulation by trans-encoded sRNAs, for example via base-pairing with target mRNAs, is a common feature in bacteria and influences various cell processes, e.g., response to stress factors. Several studies based on computational and RNA-seq approaches identified approximately 180 trans-encoded sRNAs in Sinorhizobium meliloti. The initial point of this report is a set of 52 trans-encoded sRNAs derived from the former studies. Sequence homology combined with structural conservation analyses were applied to elucidate the occurrence and distribution of conserved trans-encoded sRNAs in the order of Rhizobiales. This approach resulted in 39 RNA family models (RFMs) which showed various taxonomic distribution patterns. Whereas the majority of RFMs was restricted to Sinorhizobium species or the Rhizobiaceae, members of a few RFMs were more widely distributed in the Rhizobiales. Access to this data is provided via the RhizoGATE portal [1,2].
Sung-taik Lee - One of the best experts on this subject based on the ideXlab platform.
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Kaistia granuli sp. nov., isolated from anaerobic granules in an upflow anaerobic sludge blanket reactor
International Journal of Systematic and Evolutionary Microbiology, 2007Co-Authors: Hae-won Lee, Qing-mei Liu, Hae-min Jung, Fengxie Jin, Sung-taik LeeAbstract:A Gram-negative, chemo-organotrophic, non-motile, non-spore-forming, rod-shaped bacterium (designated strain Ko04T) was isolated from anaerobic granules in an upflow anaerobic sludge blanket reactor, and was investigated using a polyphasic taxonomic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Ko04T belongs to the order Rhizobiales in the Alphaproteobacteria. Comparative 16S rRNA gene sequence analysis showed that strain Ko04T was most closely related to Kaistia adipata (97.5 %) and that sequence similarities with other species of Rhizobiales with validly published names were less than 92.5 %. The predominant ubiquinone was Q-10 and the major fatty acids were C18 : 1 ω7c/ω9t/ω12t, C19 : 0 cyclo ω8c and C18 : 0. The G+C content of the genomic DNA of strain Ko04T was 67.8 mol%. The level of DNA–DNA relatedness with K. adipata Chj404T was 15 %. The results of the genotypic analyses in combination with chemotaxonomic and physiological data demonstrated that strain Ko04T represents a novel species within the genus Kaistia, for which the name Kaistia granuli sp. nov. is proposed. The type strain is Ko04T (=KCTC 12575T=LMG 23410T).
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Kaistia granuli sp. nov., isolated from anaerobic granules in an upflow anaerobic sludge blanket reactor.
International journal of systematic and evolutionary microbiology, 2007Co-Authors: Hae-won Lee, Qing-mei Liu, Hae-min Jung, Fengxie Jin, Sung-taik LeeAbstract:A Gram-negative, chemo-organotrophic, non-motile, non-spore-forming, rod-shaped bacterium (designated strain Ko04(T)) was isolated from anaerobic granules in an upflow anaerobic sludge blanket reactor, and was investigated using a polyphasic taxonomic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Ko04(T) belongs to the order Rhizobiales in the Alphaproteobacteria. Comparative 16S rRNA gene sequence analysis showed that strain Ko04(T) was most closely related to Kaistia adipata (97.5 %) and that sequence similarities with other species of Rhizobiales with validly published names were less than 92.5 %. The predominant ubiquinone was Q-10 and the major fatty acids were C(18 : 1)omega7c/omega9t/omega12t, C(19 : 0 )cyclo omega8c and C(18 : 0). The G+C content of the genomic DNA of strain Ko04(T) was 67.8 mol%. The level of DNA-DNA relatedness with K. adipata Chj404(T) was 15 %. The results of the genotypic analyses in combination with chemotaxonomic and physiological data demonstrated that strain Ko04(T) represents a novel species within the genus Kaistia, for which the name Kaistia granuli sp. nov. is proposed. The type strain is Ko04(T) (=KCTC 12575(T)=LMG 23410(T)).
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Pleomorphomonas koreensis sp. nov., a nitrogen-fixing species in the order Rhizobiales
International Journal of Systematic and Evolutionary Microbiology, 2006Co-Authors: Seong-hye Kim, Myung Kyum Kim, Leonid N. Ten, Sung-taik LeeAbstract:A Gram-negative, non-motile, non-spore-forming, rod-shaped bacterium (strain Y9T) was isolated from a contaminated culture of the phototrophic bacterium Rhodopseudomonas palustris, and was investigated using a polyphasic taxonomic approach. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain Y9T belonged to the order Rhizobiales in the Alphaproteobacteria. Comparison of phylogenetic data indicated that it was most closely related to Pleomorphomonas oryzae (98.5 % similarity of 16S rRNA gene sequence), and the phylogenetic distance from any other species of the order Rhizobiales with a validly published name was greater than 7.5 % (i.e. less than 92.5 % similarity). The predominant ubiquinone was Q-10 and the major fatty acids were C18 : 1, C16 : 0, C19 : 0 cyclo ω8c and C18 : 0. The G+C content of genomic DNA of strain Y9T was 65.1 mol%. The results of DNA–DNA hybridization in combination with chemotaxonomic and physiological data demonstrated that strain Y9T represents a novel species within the genus Pleomorphomonas, for which the name Pleomorphomonas koreensis sp. nov. is proposed. The type strain is Y9T (=KCTC 12246T=NBRC 100803T)
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Pleomorphomonas koreensis sp. nov., a nitrogen-fixing species in the order Rhizobiales.
International journal of systematic and evolutionary microbiology, 2006Co-Authors: Seong-hye Kim, Myung Kyum Kim, Leonid N. Ten, Sung-taik LeeAbstract:A Gram-negative, non-motile, non-spore-forming, rod-shaped bacterium (strain Y9(T)) was isolated from a contaminated culture of the phototrophic bacterium Rhodopseudomonas palustris, and was investigated using a polyphasic taxonomic approach. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain Y9(T) belonged to the order Rhizobiales in the Alphaproteobacteria. Comparison of phylogenetic data indicated that it was most closely related to Pleomorphomonas oryzae (98.5 % similarity of 16S rRNA gene sequence), and the phylogenetic distance from any other species of the order Rhizobiales with a validly published name was greater than 7.5 % (i.e. less than 92.5 % similarity). The predominant ubiquinone was Q-10 and the major fatty acids were C(18 : 1), C(16 : 0), C(19 : 0) cyclo omega8c and C(18 : 0). The G+C content of genomic DNA of strain Y9(T) was 65.1 mol%. The results of DNA-DNA hybridization in combination with chemotaxonomic and physiological data demonstrated that strain Y9(T) represents a novel species within the genus Pleomorphomonas, for which the name Pleomorphomonas koreensis sp. nov. is proposed. The type strain is Y9(T) (=KCTC 12246(T)=NBRC 100803(T)).
Elizaveta Krol - One of the best experts on this subject based on the ideXlab platform.
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Stable inheritance of Sinorhizobium meliloti cell growth polarity requires an FtsN-like protein and an amidase.
Nature communications, 2021Co-Authors: Elizaveta Krol, Lisa Stuckenschneider, Joana M. Kästle Silva, Peter L. Graumann, Anke BeckerAbstract:In Rhizobiales bacteria, such as Sinorhizobium meliloti, cell elongation takes place only at new cell poles, generated by cell division. Here, we show that the role of the FtsN-like protein RgsS in S. meliloti extends beyond cell division. RgsS contains a conserved SPOR domain known to bind amidase-processed peptidoglycan. This part of RgsS and peptidoglycan amidase AmiC are crucial for reliable selection of the new cell pole as cell elongation zone. Absence of these components increases mobility of RgsS molecules, as well as abnormal RgsS accumulation and positioning of the growth zone at the old cell pole in about one third of the cells. These cells with inverted growth polarity are able to complete the cell cycle but show partially impaired chromosome segregation. We propose that amidase-processed peptidoglycan provides a landmark for RgsS to generate cell polarity in unipolarly growing Rhizobiales. In Sinorhizobium bacteria, cell elongation takes place only at new cell poles, generated by cell division. Here, Krol et al. show that an FtsN-like protein and a peptidoglycan amidase are crucial for reliable selection of the new cell pole as cell elongation zone.
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Tol-Pal System and Rgs Proteins Interact to Promote Unipolar Growth and Cell Division in Sinorhizobium meliloti
mBio, 2020Co-Authors: Elizaveta Krol, Hamish C. L. Yau, Marcus Lechner, Simon Schäper, Gert Bange, Waldemar Vollmer, Anke BeckerAbstract:Sinorhizobium meliloti is an alphaproteobacterium belonging to the Rhizobiales Bacteria from this order elongate their cell wall at the new cell pole, generated by cell division. Screening for protein interaction partners of the previously characterized polar growth factors RgsP and RgsM, we identified the inner membrane components of the Tol-Pal system (TolQ and TolR) and novel Rgs (rhizobial growth and septation) proteins with unknown functions. TolQ, Pal, and all Rgs proteins, except for RgsE, were indispensable for S. meliloti cell growth. Six of the Rgs proteins, TolQ, and Pal localized to the growing cell pole in the cell elongation phase and to the septum in predivisional cells, and three Rgs proteins localized to the growing cell pole only. The putative FtsN-like protein RgsS contains a conserved SPOR domain and is indispensable at the early stages of cell division. The components of the Tol-Pal system were required at the late stages of cell division. RgsE, a homolog of the Agrobacterium tumefaciens growth pole ring protein GPR, has an important role in maintaining the normal growth rate and rod cell shape. RgsD is a periplasmic protein with the ability to bind peptidoglycan. Analysis of the phylogenetic distribution of the Rgs proteins showed that they are conserved in Rhizobiales and mostly absent from other alphaproteobacterial orders, suggesting a conserved role of these proteins in polar growth.IMPORTANCE Bacterial cell proliferation involves cell growth and septum formation followed by cell division. For cell growth, bacteria have evolved different complex mechanisms. The most prevalent growth mode of rod-shaped bacteria is cell elongation by incorporating new peptidoglycans in a dispersed manner along the sidewall. A small share of rod-shaped bacteria, including the alphaproteobacterial Rhizobiales, grow unipolarly. Here, we identified and initially characterized a set of Rgs (rhizobial growth and septation) proteins, which are involved in cell division and unipolar growth of Sinorhizobium meliloti and highly conserved in Rhizobiales Our data expand the knowledge of components of the polarly localized machinery driving cell wall growth and suggest a complex of Rgs proteins with components of the divisome, differing in composition between the polar cell elongation zone and the septum.
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Tol-Pal system and Rgs proteins interact to promote unipolar growth and cell division in Sinorhizobium meliloti
2020Co-Authors: Elizaveta Krol, Hamish C. L. Yau, Marcus Lechner, Simon Schäper, Gert Bange, Waldemar Vollmer, Anke BeckerAbstract:Sinorhizobium meliloti is an α-proteobacterium belonging to the Rhizobiales. Bacteria from this order elongate their cell wall at the new cell pole, generated by cell division. Screening for protein interaction partners of the previously characterized polar growth factors RgsP and RgsM, we identified the inner membrane components of the Tol-Pal system (TolQ and TolR) and novel Rgs (rhizobial growth and septation) proteins with unknown functions. TolQ, Pal and all Rgs proteins, except for RgsE, were indispensable for S. meliloti cell growth. Six of the Rgs proteins, TolQ and Pal localized to the growing cell pole in the cell elongation phase and to the septum in pre-divisional cells, and three Rgs proteins localized to growing cell pole only. The FtsN-like protein RgsS contains a conserved SPOR domain and is indispensable at the early stages of cell division. The components of the Tol-Pal system were required at the late stages of cell division. RgsE, a homolog of the Agrobacterium tumefaciens growth pole ring protein GPR, has an important role in maintaining the normal growth rate and rod cell shape. RgsD is a novel periplasmic protein with the ability to bind peptidoglycan. Analysis of the phylogenetic distribution of novel Rgs proteins showed that they are conserved in Rhizobiales and mostly absent from other α-proteobacterial orders, suggesting a conserved role of these proteins in polar growth.
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Seven-transmembrane receptor protein RgsP and cell wall-binding protein RgsM promote unipolar growth in Rhizobiales.
PLOS Genetics, 2018Co-Authors: Simon Schäper, Elizaveta Krol, Hamish C. L. Yau, Waldemar Vollmer, Dorota Skotnicka, Thomas Heimerl, Joe Gray, Volkhard Kaever, Lotte Søgaard-andersen, Anke BeckerAbstract:Members of the Rhizobiales (class of α-proteobacteria) display zonal peptidoglycan cell wall growth at one cell pole, contrasting with the dispersed mode of cell wall growth along the sidewalls of many other rod-shaped bacteria. Here, we show that the seven-transmembrane receptor (7TMR) protein RgsP (SMc00074), together with the putative membrane-anchored peptidoglycan metallopeptidase RgsM (SMc02432), have key roles in unipolar peptidoglycan formation during growth and at mid-cell during cell division in Sinorhizobium meliloti. RgsP is composed of a periplasmic globular 7TMR-DISMED2 domain, a membrane-spanning region, and cytoplasmic PAS, GGDEF and EAL domains. The EAL domain confers phosphodiesterase activity towards the second messenger cyclic di-GMP, a key regulatory player in the transition between bacterial lifestyles. RgsP and RgsM localize to sites of zonal cell wall synthesis at the new cell pole and cell divison site, suggesting a role in cell wall biogenesis. The two proteins are essential for cell wall biogenesis and cell growth. Cells depleted of RgsP or RgsM had an altered muropeptide composition and RgsM binds to peptidoglycan. RgsP and RgsM orthologs are functional when interchanged between α-rhizobial species pointing to a conserved mechanism for cell wall biogenesis/remodeling within the Rhizobiales. Overall, our findings suggest that RgsP and RgsM contribute to the regulation of unipolar cell wall biogenesis in α-rhizobia.
Jody W. Deming - One of the best experts on this subject based on the ideXlab platform.
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The genetic potential for key biogeochemical processes in Arctic frost flowers and young sea ice revealed by metagenomic analysis
FEMS Microbiology Ecology, 2014Co-Authors: Jeff S. Bowman, Chris T. Berthiaume, E. Virginia Armbrust, Jody W. DemingAbstract:Newly formed sea ice is a vast and biogeochemically active environment. Recently, we reported an unusual microbial community dominated by members of the Rhizobiales in frost flowers at the surface of Arctic young sea ice based on the presence of 16S gene sequences related to these strains. Here, we use metagenomic analysis of two samples, from a field of frost flowers and the underlying young sea ice, to explore the metabolic potential of this surface ice community. The analysis links genes for key biogeochemical processes to the Rhizobiales, including dimethylsulfide uptake, betaine glycine turnover, and halocarbon production. Nodulation and nitrogen fixation genes characteristic of terrestrial root-nodulating Rhizobiales were generally lacking from these metagenomes. Non-Rhizobiales clades at the ice surface had genes that would enable additional biogeochemical processes, including mercury reduction and dimethylsulfoniopropionate catabolism. Although the ultimate source of the observed microbial community is not known, considerations of the possible role of eolian deposition or transport with particles entrained during ice formation favor a suspended particle source for this microbial community.
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Selective occurrence of Rhizobiales in frost flowers on the surface of young sea ice near Barrow, Alaska and distribution in the polar marine rare biosphere.
Environmental Microbiology Reports, 2013Co-Authors: Jeff S. Bowman, Catherine Larose, Timothy M. Vogel, Jody W. DemingAbstract:Frost flowers are highly saline ice structures that grow on the surface of young sea ice, a spatially extensive environment of increasing importance in the Arctic Ocean. In a previous study, we reported organic components of frost flowers in the form of elevated levels of bacteria and exopolymers relative to underlying ice. Here, DNA was extracted from frost flowers and young sea ice, collected in springtime from a frozen lead offshore of Barrow, Alaska, to identify bacteria in these understudied environments. Evaluation of the distribution of 16S rRNA genes via four methods (microarray analysis, T-RFLP, clone library and shotgun metagenomic sequencing) indicated distinctive bacterial assemblages between the two environments, with frost flowers appearing to select for Rhizobiales. A phylogenetic placement approach, used to evaluate the distribution of similar Rhizobiales sequences in other polar marine studies, indicated that some of the observed strains represent widely distributed members of the marine rare biosphere in both the Arctic and Antarctic.
Simon Schäper - One of the best experts on this subject based on the ideXlab platform.
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Tol-Pal System and Rgs Proteins Interact to Promote Unipolar Growth and Cell Division in Sinorhizobium meliloti
mBio, 2020Co-Authors: Elizaveta Krol, Hamish C. L. Yau, Marcus Lechner, Simon Schäper, Gert Bange, Waldemar Vollmer, Anke BeckerAbstract:Sinorhizobium meliloti is an alphaproteobacterium belonging to the Rhizobiales Bacteria from this order elongate their cell wall at the new cell pole, generated by cell division. Screening for protein interaction partners of the previously characterized polar growth factors RgsP and RgsM, we identified the inner membrane components of the Tol-Pal system (TolQ and TolR) and novel Rgs (rhizobial growth and septation) proteins with unknown functions. TolQ, Pal, and all Rgs proteins, except for RgsE, were indispensable for S. meliloti cell growth. Six of the Rgs proteins, TolQ, and Pal localized to the growing cell pole in the cell elongation phase and to the septum in predivisional cells, and three Rgs proteins localized to the growing cell pole only. The putative FtsN-like protein RgsS contains a conserved SPOR domain and is indispensable at the early stages of cell division. The components of the Tol-Pal system were required at the late stages of cell division. RgsE, a homolog of the Agrobacterium tumefaciens growth pole ring protein GPR, has an important role in maintaining the normal growth rate and rod cell shape. RgsD is a periplasmic protein with the ability to bind peptidoglycan. Analysis of the phylogenetic distribution of the Rgs proteins showed that they are conserved in Rhizobiales and mostly absent from other alphaproteobacterial orders, suggesting a conserved role of these proteins in polar growth.IMPORTANCE Bacterial cell proliferation involves cell growth and septum formation followed by cell division. For cell growth, bacteria have evolved different complex mechanisms. The most prevalent growth mode of rod-shaped bacteria is cell elongation by incorporating new peptidoglycans in a dispersed manner along the sidewall. A small share of rod-shaped bacteria, including the alphaproteobacterial Rhizobiales, grow unipolarly. Here, we identified and initially characterized a set of Rgs (rhizobial growth and septation) proteins, which are involved in cell division and unipolar growth of Sinorhizobium meliloti and highly conserved in Rhizobiales Our data expand the knowledge of components of the polarly localized machinery driving cell wall growth and suggest a complex of Rgs proteins with components of the divisome, differing in composition between the polar cell elongation zone and the septum.
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Tol-Pal system and Rgs proteins interact to promote unipolar growth and cell division in Sinorhizobium meliloti
2020Co-Authors: Elizaveta Krol, Hamish C. L. Yau, Marcus Lechner, Simon Schäper, Gert Bange, Waldemar Vollmer, Anke BeckerAbstract:Sinorhizobium meliloti is an α-proteobacterium belonging to the Rhizobiales. Bacteria from this order elongate their cell wall at the new cell pole, generated by cell division. Screening for protein interaction partners of the previously characterized polar growth factors RgsP and RgsM, we identified the inner membrane components of the Tol-Pal system (TolQ and TolR) and novel Rgs (rhizobial growth and septation) proteins with unknown functions. TolQ, Pal and all Rgs proteins, except for RgsE, were indispensable for S. meliloti cell growth. Six of the Rgs proteins, TolQ and Pal localized to the growing cell pole in the cell elongation phase and to the septum in pre-divisional cells, and three Rgs proteins localized to growing cell pole only. The FtsN-like protein RgsS contains a conserved SPOR domain and is indispensable at the early stages of cell division. The components of the Tol-Pal system were required at the late stages of cell division. RgsE, a homolog of the Agrobacterium tumefaciens growth pole ring protein GPR, has an important role in maintaining the normal growth rate and rod cell shape. RgsD is a novel periplasmic protein with the ability to bind peptidoglycan. Analysis of the phylogenetic distribution of novel Rgs proteins showed that they are conserved in Rhizobiales and mostly absent from other α-proteobacterial orders, suggesting a conserved role of these proteins in polar growth.
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Seven-transmembrane receptor protein RgsP and cell wall-binding protein RgsM promote unipolar growth in Rhizobiales.
PLOS Genetics, 2018Co-Authors: Simon Schäper, Elizaveta Krol, Hamish C. L. Yau, Waldemar Vollmer, Dorota Skotnicka, Thomas Heimerl, Joe Gray, Volkhard Kaever, Lotte Søgaard-andersen, Anke BeckerAbstract:Members of the Rhizobiales (class of α-proteobacteria) display zonal peptidoglycan cell wall growth at one cell pole, contrasting with the dispersed mode of cell wall growth along the sidewalls of many other rod-shaped bacteria. Here, we show that the seven-transmembrane receptor (7TMR) protein RgsP (SMc00074), together with the putative membrane-anchored peptidoglycan metallopeptidase RgsM (SMc02432), have key roles in unipolar peptidoglycan formation during growth and at mid-cell during cell division in Sinorhizobium meliloti. RgsP is composed of a periplasmic globular 7TMR-DISMED2 domain, a membrane-spanning region, and cytoplasmic PAS, GGDEF and EAL domains. The EAL domain confers phosphodiesterase activity towards the second messenger cyclic di-GMP, a key regulatory player in the transition between bacterial lifestyles. RgsP and RgsM localize to sites of zonal cell wall synthesis at the new cell pole and cell divison site, suggesting a role in cell wall biogenesis. The two proteins are essential for cell wall biogenesis and cell growth. Cells depleted of RgsP or RgsM had an altered muropeptide composition and RgsM binds to peptidoglycan. RgsP and RgsM orthologs are functional when interchanged between α-rhizobial species pointing to a conserved mechanism for cell wall biogenesis/remodeling within the Rhizobiales. Overall, our findings suggest that RgsP and RgsM contribute to the regulation of unipolar cell wall biogenesis in α-rhizobia.
