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Olaf Schneewind - One of the best experts on this subject based on the ideXlab platform.
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signal peptides direct Surface Proteins to two distinct envelope locations of staphylococcus aureus
The EMBO Journal, 2008Co-Authors: Andrea C. Dedent, Dominique Missiakas, Taeok Bae, Olaf SchneewindAbstract:Surface Proteins of Gram-positive bacteria are covalently linked to the cell wall envelope by a mechanism requiring an N-terminal signal peptide and a C-terminal LPXTG motif sorting signal. We show here that Surface Proteins of Staphylococcus aureus arrive at two distinct destinations in the bacterial envelope, either distributed as a ring surrounding each cell or as discrete assembly sites. Proteins with ring-like distribution (clumping factor A (ClfA), Spa, fibronectin-binding protein B (FnbpB), serine-aspartate repeat protein C (SdrC) and SdrD) harbour signal peptides with a YSIRK/GS motif, whereas Proteins directed to discrete assembly sites (S. aureus Surface protein A (SasA), SasD, SasF and SasK) do not. Reciprocal exchange of signal peptides between Surface Proteins with (ClfA) or without the YSIRK/GS motif (SasF) directed recombinant products to the alternate destination, whereas mutations that altered only the YSIRK sequence had no effect. Our observations suggest that S. aureus distinguishes between signal peptides to address Proteins to either the cell pole (signal peptides without YSIRK/GS) or the cross wall, the peptidoglycan layer that forms during cell division to separate new daughter cells (signal peptides with YISRK/GS motif).
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Surface Proteins and exotoxins are required for the pathogenesis of staphylococcus aureus pneumonia
Infection and Immunity, 2007Co-Authors: Juliane Bubeck Wardenburg, Ravi J Patel, Olaf SchneewindAbstract:A model of Staphylococcus aureus-induced pneumonia in adult, immunocompetent C57BL/6J mice is described. This model closely mimics the clinical and pathological features of pneumonia in human patients. Using this system, we defined a role for S. aureus strain Newman Surface Proteins and secreted exotoxins in pneumonia-related mortality.
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Vaccine assembly from Surface Proteins of Staphylococcus aureus.
Proceedings of the National Academy of Sciences, 2006Co-Authors: Yukiko Stranger-jones, Taeok Bae, Olaf SchneewindAbstract:Staphylococcus aureus is the most common cause of hospital-acquired infection. Because of the emergence of antibiotic-resistant strains, these infections represent a serious public health threat. To develop a broadly protective vaccine, we tested cell wall-anchored Surface Proteins of S. aureus as antigens in a murine model of abscess formation. Immunization with four antigens (IsdA, IsdB, SdrD, and SdrE) generated significant protective immunity that correlated with the induction of opsonophagocytic antibodies. When assembled into a combined vaccine, the four Surface Proteins afforded high levels of protection against invasive disease or lethal challenge with human clinical S. aureus isolates.
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bacillus anthracis sortase a srta anchors lpxtg motif containing Surface Proteins to the cell wall envelope
Journal of Bacteriology, 2005Co-Authors: Andrew H Gaspar, Elizabeth M Glass, Kristin L Debord, Luciano A Marraffini, Hung Tonthat, Olaf SchneewindAbstract:Cell wall-anchored Surface Proteins of gram-positive pathogens play important roles during the establishment of many infectious diseases, but the contributions of Surface Proteins to the pathogenesis of anthrax have not yet been revealed. Cell wall anchoring in Staphylococcus aureus occurs by a transpeptidation mechanism requiring Surface Proteins with C-terminal sorting signals as well as sortase enzymes. The genome sequence of Bacillus anthracis encodes three sortase genes and eleven Surface Proteins with different types of cell wall sorting signals. Purified B. anthracis sortase A cleaved peptides encompassing LPXTG motif-type sorting signals between the threonine (T) and the glycine (G) residues in vitro. Sortase A activity could be inhibited by thiol-reactive reagents, similar to staphylococcal sortases. B. anthracis parent strain Sterne 34F2, but not variants lacking the srtA gene, anchored the collagen-binding MSCRAMM (microbial Surface components recognizing adhesive matrix molecules) BasC (BA5258/BAS4884) to the bacterial cell wall. These results suggest that B. anthracis SrtA anchors Surface Proteins bearing LPXTG motif sorting signals to the cell wall envelope of vegetative bacilli.
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inactivation of the srta gene in listeria monocytogenes inhibits anchoring of Surface Proteins and affects virulence
Molecular Microbiology, 2002Co-Authors: Helene Bierne, Matthias Trost, Graciela M Pucciarelli, Lothar Jansch, Pierre Dehoux, Olaf Schneewind, Sarkis K Mazmanian, Francisco García-del Portillo, Pascale CossartAbstract:Summary During infection of their hosts, Gram-positive bac-teria express Surface Proteins that serve multiple biological functions. Surface Proteins harbouring a C-terminal sorting signal with an LPXTG motif are covalently linked to the cell wall peptidoglycan by a transamidase named sortase. Two genes encoding putative sortases, termed srtA and srtB, were identified in the genome of the intracellular pathogenic bacterium Listeria monocytogenes. Inactivation of srtA abolishes anchoring of the invasion protein InlA to the bacterial Surface. It also prevents the proper sorting of several other peptidoglycan-associated LPXTG Proteins. Three were identified by a mass spectrometry approach. The ΔsrtA mutant strain is defective in entering epithelial cells, similar to a ΔinlA mutant. In contrast to a ΔinlA mutant, the ΔsrtA mutant is impaired for colonization of the liver and spleen after oral inoculation in mice. Thus, L. monocytogenes srtA is required for the cell wall anchoring of InlA and, presumably, for the anchoring of other LPXTG-containing Proteins that are involved in listerial infections.
Sarkis K Mazmanian - One of the best experts on this subject based on the ideXlab platform.
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inactivation of the srta gene in listeria monocytogenes inhibits anchoring of Surface Proteins and affects virulence
Molecular Microbiology, 2002Co-Authors: Helene Bierne, Matthias Trost, Graciela M Pucciarelli, Lothar Jansch, Pierre Dehoux, Olaf Schneewind, Sarkis K Mazmanian, Francisco García-del Portillo, Pascale CossartAbstract:Summary During infection of their hosts, Gram-positive bac-teria express Surface Proteins that serve multiple biological functions. Surface Proteins harbouring a C-terminal sorting signal with an LPXTG motif are covalently linked to the cell wall peptidoglycan by a transamidase named sortase. Two genes encoding putative sortases, termed srtA and srtB, were identified in the genome of the intracellular pathogenic bacterium Listeria monocytogenes. Inactivation of srtA abolishes anchoring of the invasion protein InlA to the bacterial Surface. It also prevents the proper sorting of several other peptidoglycan-associated LPXTG Proteins. Three were identified by a mass spectrometry approach. The ΔsrtA mutant strain is defective in entering epithelial cells, similar to a ΔinlA mutant. In contrast to a ΔinlA mutant, the ΔsrtA mutant is impaired for colonization of the liver and spleen after oral inoculation in mice. Thus, L. monocytogenes srtA is required for the cell wall anchoring of InlA and, presumably, for the anchoring of other LPXTG-containing Proteins that are involved in listerial infections.
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sortase catalysed anchoring of Surface Proteins to the cell wall of staphylococcus aureus
Molecular Microbiology, 2001Co-Authors: Sarkis K Mazmanian, Hung Tonthat, Olaf SchneewindAbstract:Many Surface Proteins of Gram-positive bacteria are anchored to the cell wall envelope by a transpeptidation mechanism, requiring a C-terminal sorting signal with a conserved LPXTG motif. Sortase, a membrane protein of Staphylococcus aureus, cleaves polypeptides between the threonine and the glycine of the LPXTG motif and catalyses the formation of an amide bond between the carboxyl-group of threonine and the amino-group of peptidoglycan cross-bridges. S. aureus mutants lacking the srtA gene fail to anchor and display some Surface Proteins and are impaired in the ability to cause animal infections. Sortase acts on Surface Proteins that are initiated into the secretion (Sec) pathway and have their signal peptide removed by signal peptidase. The S. aureus genome encodes two sets of sortase and secretion genes. It is conceivable that S. aureus has evolved more than one pathway for the transport of 20 Surface Proteins to the cell wall envelope.
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staphylococcus aureus sortase mutants defective in the display of Surface Proteins and in the pathogenesis of animal infections
Proceedings of the National Academy of Sciences of the United States of America, 2000Co-Authors: Sarkis K Mazmanian, Eric R Jensen, Eileen Lenoy, Olaf SchneewindAbstract:Many Gram-positive bacteria covalently tether their Surface adhesins to the cell wall peptidoglycan. We find that Surface Proteins of Staphylococcus aureus are linked to the cell wall by sortase, an enzyme that cleaves polypeptides at a conserved LPXTG motif. S. aureus mutants lacking sortase fail to process and display Surface Proteins and are defective in the establishment of infections. Thus, the cell wall envelope of Gram-positive bacteria represents a Surface organelle responsible for interactions with the host environment during the pathogenesis of bacterial infections.
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anchoring of Surface Proteins to the cell wall of staphylococcus aureus sortase catalyzed in vitro transpeptidation reaction using lpxtg peptide and nh2 gly3 substrates
Journal of Biological Chemistry, 2000Co-Authors: Hung Tonthat, Sarkis K Mazmanian, Kym F Faull, Olaf SchneewindAbstract:Staphylococcus aureus sortase anchors Surface Proteins to the cell wall envelope by cleaving polypeptides at the LPXTG motif. Surface Proteins are linked to the peptidoglycan by an amide bond between the C-terminal carboxyl and the amino group of the pentaglycine cross-bridge. We find that purified recombinant sortase hydrolyzed peptides bearing an LPXTG motif at the peptide bond between threonine and glycine. In the presence of NH2-Gly3, sortase catalyzed exclusively a transpeptidation reaction, linking the carboxyl group of threonine to the amino group of NH2-Gly3. In the presence of amino group donors the rate of sortase mediated cleavage at the LPXTG motif was increased. Hydrolysis and transpeptidation required the sulfhydryl of cysteine 184, suggesting that sortase catalyzed the transpeptidation reaction of Surface protein anchoring via the formation of a thioester acyl-enzyme intermediate.
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purification and characterization of sortase the transpeptidase that cleaves Surface Proteins of staphylococcus aureus at the lpxtg motif
Proceedings of the National Academy of Sciences of the United States of America, 1999Co-Authors: Hung Tonthat, Sarkis K Mazmanian, Kym F Faull, Olaf SchneewindAbstract:Surface Proteins of Staphylococcus aureus are linked to the bacterial cell wall by sortase, an enzyme that cleaves polypeptides at the threonine of the LPXTG motif. Surface Proteins can be released from staphylococci by treatment with hydroxylamine, resulting in the formation of threonine hydroxamate. Staphylococcal extracts, as well as purified sortase, catalyze the hydroxylaminolysis of peptides bearing an LPXTG motif, a reaction that can be inhibited with sulfhydryl-modifying reagents. Replacement of the single conserved cysteine at position 184 of sortase with alanine abolishes enzyme activity. Thus, sortase appears to catalyze Surface-protein anchoring by means of a transpeptidation reaction that captures cleaved polypeptides as thioester enzyme intermediates.
Hung Tonthat - One of the best experts on this subject based on the ideXlab platform.
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bacillus anthracis sortase a srta anchors lpxtg motif containing Surface Proteins to the cell wall envelope
Journal of Bacteriology, 2005Co-Authors: Andrew H Gaspar, Elizabeth M Glass, Kristin L Debord, Luciano A Marraffini, Hung Tonthat, Olaf SchneewindAbstract:Cell wall-anchored Surface Proteins of gram-positive pathogens play important roles during the establishment of many infectious diseases, but the contributions of Surface Proteins to the pathogenesis of anthrax have not yet been revealed. Cell wall anchoring in Staphylococcus aureus occurs by a transpeptidation mechanism requiring Surface Proteins with C-terminal sorting signals as well as sortase enzymes. The genome sequence of Bacillus anthracis encodes three sortase genes and eleven Surface Proteins with different types of cell wall sorting signals. Purified B. anthracis sortase A cleaved peptides encompassing LPXTG motif-type sorting signals between the threonine (T) and the glycine (G) residues in vitro. Sortase A activity could be inhibited by thiol-reactive reagents, similar to staphylococcal sortases. B. anthracis parent strain Sterne 34F2, but not variants lacking the srtA gene, anchored the collagen-binding MSCRAMM (microbial Surface components recognizing adhesive matrix molecules) BasC (BA5258/BAS4884) to the bacterial cell wall. These results suggest that B. anthracis SrtA anchors Surface Proteins bearing LPXTG motif sorting signals to the cell wall envelope of vegetative bacilli.
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sortase catalysed anchoring of Surface Proteins to the cell wall of staphylococcus aureus
Molecular Microbiology, 2001Co-Authors: Sarkis K Mazmanian, Hung Tonthat, Olaf SchneewindAbstract:Many Surface Proteins of Gram-positive bacteria are anchored to the cell wall envelope by a transpeptidation mechanism, requiring a C-terminal sorting signal with a conserved LPXTG motif. Sortase, a membrane protein of Staphylococcus aureus, cleaves polypeptides between the threonine and the glycine of the LPXTG motif and catalyses the formation of an amide bond between the carboxyl-group of threonine and the amino-group of peptidoglycan cross-bridges. S. aureus mutants lacking the srtA gene fail to anchor and display some Surface Proteins and are impaired in the ability to cause animal infections. Sortase acts on Surface Proteins that are initiated into the secretion (Sec) pathway and have their signal peptide removed by signal peptidase. The S. aureus genome encodes two sets of sortase and secretion genes. It is conceivable that S. aureus has evolved more than one pathway for the transport of 20 Surface Proteins to the cell wall envelope.
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anchoring of Surface Proteins to the cell wall of staphylococcus aureus sortase catalyzed in vitro transpeptidation reaction using lpxtg peptide and nh2 gly3 substrates
Journal of Biological Chemistry, 2000Co-Authors: Hung Tonthat, Sarkis K Mazmanian, Kym F Faull, Olaf SchneewindAbstract:Staphylococcus aureus sortase anchors Surface Proteins to the cell wall envelope by cleaving polypeptides at the LPXTG motif. Surface Proteins are linked to the peptidoglycan by an amide bond between the C-terminal carboxyl and the amino group of the pentaglycine cross-bridge. We find that purified recombinant sortase hydrolyzed peptides bearing an LPXTG motif at the peptide bond between threonine and glycine. In the presence of NH2-Gly3, sortase catalyzed exclusively a transpeptidation reaction, linking the carboxyl group of threonine to the amino group of NH2-Gly3. In the presence of amino group donors the rate of sortase mediated cleavage at the LPXTG motif was increased. Hydrolysis and transpeptidation required the sulfhydryl of cysteine 184, suggesting that sortase catalyzed the transpeptidation reaction of Surface protein anchoring via the formation of a thioester acyl-enzyme intermediate.
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purification and characterization of sortase the transpeptidase that cleaves Surface Proteins of staphylococcus aureus at the lpxtg motif
Proceedings of the National Academy of Sciences of the United States of America, 1999Co-Authors: Hung Tonthat, Sarkis K Mazmanian, Kym F Faull, Olaf SchneewindAbstract:Surface Proteins of Staphylococcus aureus are linked to the bacterial cell wall by sortase, an enzyme that cleaves polypeptides at the threonine of the LPXTG motif. Surface Proteins can be released from staphylococci by treatment with hydroxylamine, resulting in the formation of threonine hydroxamate. Staphylococcal extracts, as well as purified sortase, catalyze the hydroxylaminolysis of peptides bearing an LPXTG motif, a reaction that can be inhibited with sulfhydryl-modifying reagents. Replacement of the single conserved cysteine at position 184 of sortase with alanine abolishes enzyme activity. Thus, sortase appears to catalyze Surface-protein anchoring by means of a transpeptidation reaction that captures cleaved polypeptides as thioester enzyme intermediates.
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staphylococcus aureus sortase an enzyme that anchors Surface Proteins to the cell wall
Science, 1999Co-Authors: Sarkis K Mazmanian, Hung Tonthat, Olaf SchneewindAbstract:Surface Proteins of Gram-positive bacteria are linked to the bacterial cell wall by a mechanism that involves cleavage of a conserved Leu-Pro-X-Thr-Gly (LPXTG) motif and that occurs during assembly of the peptidoglycan cell wall. A Staphylococcus aureus mutant defective in the anchoring of Surface Proteins was isolated and shown to carry a mutation in the srtA gene. Overexpression of srtA increased the rate of Surface protein anchoring, and homologs of srtA were found in other pathogenic Gram-positive bacteria. The protein specified by srtA, sortase, may be a useful target for the development of new antimicrobial drugs.
Kym F Faull - One of the best experts on this subject based on the ideXlab platform.
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anchoring of Surface Proteins to the cell wall of staphylococcus aureus sortase catalyzed in vitro transpeptidation reaction using lpxtg peptide and nh2 gly3 substrates
Journal of Biological Chemistry, 2000Co-Authors: Hung Tonthat, Sarkis K Mazmanian, Kym F Faull, Olaf SchneewindAbstract:Staphylococcus aureus sortase anchors Surface Proteins to the cell wall envelope by cleaving polypeptides at the LPXTG motif. Surface Proteins are linked to the peptidoglycan by an amide bond between the C-terminal carboxyl and the amino group of the pentaglycine cross-bridge. We find that purified recombinant sortase hydrolyzed peptides bearing an LPXTG motif at the peptide bond between threonine and glycine. In the presence of NH2-Gly3, sortase catalyzed exclusively a transpeptidation reaction, linking the carboxyl group of threonine to the amino group of NH2-Gly3. In the presence of amino group donors the rate of sortase mediated cleavage at the LPXTG motif was increased. Hydrolysis and transpeptidation required the sulfhydryl of cysteine 184, suggesting that sortase catalyzed the transpeptidation reaction of Surface protein anchoring via the formation of a thioester acyl-enzyme intermediate.
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Anchor Structure of Cell Wall Surface Proteins in Listeria monocytogenes
Biochemistry, 2000Co-Authors: Gautam Dhar, Kym F Faull, Olaf SchneewindAbstract:Many Surface Proteins of Gram-positive bacteria are anchored to the cell wall by a mechanism requiring a COOH-terminal sorting signal with a conserved LPXTG motif. In Staphylococcus aureus, Surface Proteins are cleaved between the threonine and the glycine of the LPXTG motif. The carboxyl of threonine is subsequently amide linked to the amino group of the pentaglycine cell wall crossbridge. Here we investigated the anchor structure of Surface Proteins in Listeria monocytogenes. A methionine and six histidines (MH6) were inserted upstream of the LPXTG motif of internalin A (InlA), a cell-wall-anchored Surface protein of L. monocytogenes. The engineered protein InlA-MH6-Cws was found anchored in the bacterial cell wall. After peptidoglycan digestion with phage endolysin, InlA-MH6-Cws was purified by affinity chromatography. COOH-terminal peptides of InlA-MH6-Cws were obtained by cyanogen bromide cleavage followed by purification on a nickel−nitriloacetic acid column. Analysis of COOH-terminal peptides with ...
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purification and characterization of sortase the transpeptidase that cleaves Surface Proteins of staphylococcus aureus at the lpxtg motif
Proceedings of the National Academy of Sciences of the United States of America, 1999Co-Authors: Hung Tonthat, Sarkis K Mazmanian, Kym F Faull, Olaf SchneewindAbstract:Surface Proteins of Staphylococcus aureus are linked to the bacterial cell wall by sortase, an enzyme that cleaves polypeptides at the threonine of the LPXTG motif. Surface Proteins can be released from staphylococci by treatment with hydroxylamine, resulting in the formation of threonine hydroxamate. Staphylococcal extracts, as well as purified sortase, catalyze the hydroxylaminolysis of peptides bearing an LPXTG motif, a reaction that can be inhibited with sulfhydryl-modifying reagents. Replacement of the single conserved cysteine at position 184 of sortase with alanine abolishes enzyme activity. Thus, sortase appears to catalyze Surface-protein anchoring by means of a transpeptidation reaction that captures cleaved polypeptides as thioester enzyme intermediates.
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Anchor Structure of Staphylococcal Surface Proteins II. COOH-TERMINAL STRUCTURE OF MURAMIDASE AND AMIDASE-SOLUBILIZED Surface PROTEIN
Journal of Biological Chemistry, 1998Co-Authors: William Wiley Navarre, Hung Ton-that, Kym F Faull, Olaf SchneewindAbstract:Abstract Surface Proteins of the Gram-positive organismStaphylococcus aureus are anchored to the bacterial cell wall by a transpeptidation mechanism during which the polypeptide is cleaved between the threonine (T) and the glycine (G) of the LPXTG motif. The carboxyl of threonine is subsequently amide linked to the amino of the pentaglycyl cross-bridge within the staphylococcal peptidoglycan. Previous work examined the anchor structure of Surface Proteins solubilized from the peptidoglycan by treatment with lysostaphin or φ11 hydrolase and identified COOH-terminally linked triglycyl orl-Ala-d-iGln-l-Lys(Gly5)-d-Ala and MurNAc-[l-Ala-d-iGln-l-Lys(Gly5)-d-Ala](β1–4)-GlcNAc, respectively. Here, we report the anchor structure of Surface Proteins solubilized with N-acetylmuramidase andN-acetylmuramyl-l-alanine amidase.N-Acetylmuramidase-released Surface protein was linked to MurNAc-[l-Ala-d-iGln-l-Lys(Gly5)-d-Ala](β1–4)-GlcNAc, whereas N-acetylmuramyl-l-alanine amidase treatment of the cell wall solubilized Surface Proteins linked tol-Ala-d-iGln-l-Lys(Gly5)-d-Ala. Most, but not all, anchor structures were cross-linked to other cell wall subunits, in which the d-alanyl at position four was amide linked to the pentaglycyl of a neighboring wall peptide.
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anchor structure of staphylococcal Surface Proteins a branched peptide that links the carboxyl terminus of Proteins to the cell wall
Journal of Biological Chemistry, 1997Co-Authors: Hung Tonthat, Kym F Faull, Olaf SchneewindAbstract:Abstract Surface Proteins of Staphylococcus aureus are anchored to the cell wall by a mechanism requiring a COOH-terminal sorting signal. Previous work demonstrated that the sorting signal is cleaved at the conserved LPXTG motif and that the carboxyl of threonine (T) is linked to the staphylococcal cell wall. By employing different cell wall lytic enzymes, Surface Proteins were released from the staphylococcal peptidoglycan and their COOH-terminal anchor structure was revealed by a combination of mass spectrometry and chemical analysis. The results demonstrate that Surface Proteins are linked to a branched peptide (NH2-Ala-γ-Gln-Lys-(NH2-Gly5)-Ala-COOH) by an amide bond between the carboxyl of threonine and the amino of the pentaglycine cross-bridge that is attached to the e-amino of lysyl. This branched anchor peptide is amide-linked to the carboxyl ofN-acetylmuramic acid, thereby tethering the COOH-terminal end of Surface Proteins to the staphylococcal peptidoglycan.
William Wiley Navarre - One of the best experts on this subject based on the ideXlab platform.
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Surface Proteins of gram positive bacteria and mechanisms of their targeting to the cell wall envelope
Microbiology and Molecular Biology Reviews, 1999Co-Authors: William Wiley Navarre, Olaf SchneewindAbstract:The cell wall envelope of gram-positive bacteria is a macromolecular, exoskeletal organelle that is assembled and turned over at designated sites. The cell wall also functions as a Surface organelle that allows gram-positive pathogens to interact with their environment, in particular the tissues of the infected host. All of these functions require that Surface Proteins and enzymes be properly targeted to the cell wall envelope. Two basic mechanisms, cell wall sorting and targeting, have been identified. Cell well sorting is the covalent attachment of Surface Proteins to the peptidoglycan via a C-terminal sorting signal that contains a consensus LPXTG sequence. More than 100 Proteins that possess cell wall-sorting signals, including the M Proteins of Streptococcus pyogenes, protein A of Staphylococcus aureus, and several internalins of Listeria monocytogenes, have been identified. Cell wall targeting involves the noncovalent attachment of Proteins to the cell Surface via specialized binding domains. Several of these wall-binding domains appear to interact with secondary wall polymers that are associated with the peptidoglycan, for example teichoic acids and polysaccharides. Proteins that are targeted to the cell Surface include muralytic enzymes such as autolysins, lysostaphin, and phage lytic enzymes. Other examples for targeted Proteins are the Surface S-layer Proteins of bacilli and clostridia, as well as virulence factors required for the pathogenesis of L. monocytogenes (internalin B) and Streptococcus pneumoniae (PspA) infections. In this review we describe the mechanisms for both sorting and targeting of Proteins to the envelope of gram-positive bacteria and review the functions of known Surface Proteins.
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Anchor Structure of Staphylococcal Surface Proteins II. COOH-TERMINAL STRUCTURE OF MURAMIDASE AND AMIDASE-SOLUBILIZED Surface PROTEIN
Journal of Biological Chemistry, 1998Co-Authors: William Wiley Navarre, Hung Ton-that, Kym F Faull, Olaf SchneewindAbstract:Abstract Surface Proteins of the Gram-positive organismStaphylococcus aureus are anchored to the bacterial cell wall by a transpeptidation mechanism during which the polypeptide is cleaved between the threonine (T) and the glycine (G) of the LPXTG motif. The carboxyl of threonine is subsequently amide linked to the amino of the pentaglycyl cross-bridge within the staphylococcal peptidoglycan. Previous work examined the anchor structure of Surface Proteins solubilized from the peptidoglycan by treatment with lysostaphin or φ11 hydrolase and identified COOH-terminally linked triglycyl orl-Ala-d-iGln-l-Lys(Gly5)-d-Ala and MurNAc-[l-Ala-d-iGln-l-Lys(Gly5)-d-Ala](β1–4)-GlcNAc, respectively. Here, we report the anchor structure of Surface Proteins solubilized with N-acetylmuramidase andN-acetylmuramyl-l-alanine amidase.N-Acetylmuramidase-released Surface protein was linked to MurNAc-[l-Ala-d-iGln-l-Lys(Gly5)-d-Ala](β1–4)-GlcNAc, whereas N-acetylmuramyl-l-alanine amidase treatment of the cell wall solubilized Surface Proteins linked tol-Ala-d-iGln-l-Lys(Gly5)-d-Ala. Most, but not all, anchor structures were cross-linked to other cell wall subunits, in which the d-alanyl at position four was amide linked to the pentaglycyl of a neighboring wall peptide.
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proteolytic cleavage and cell wall anchoring at the lpxtg motif of Surface Proteins in gram positive bacteria
Molecular Microbiology, 1994Co-Authors: William Wiley Navarre, Olaf SchneewindAbstract:Many Surface Proteins are thought to be anchored to the cell wall of Gram-positive bacteria via their C-terminus. Cell wall anchoring requires a specific sorting signal, normally located at the predicted C-terminus of Surface Proteins. Here we show that when placed into the middle of a polypeptide chain, the sorting signal causes the specific cleavage of the precursor as well as the cell wall anchoring of its N-terminal fragment, while the C-terminal fragment remains within the cytoplasm. N-terminal sequencing of the C-terminal cleavage fragment suggests that the cleavage site is located between threonine (T) and glycine (G) of the LPXTG motif, the signature sequence of cell wall sorting signals. All Surface Proteins harbouring an LPXTG sequence motif may therefore be cleaved and anchored by a universal mechanism. We also propose a novel hypothesis for the cell wall linkage of Surface Proteins in Gram-positive bacteria.
