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C R Hutchinson - One of the best experts on this subject based on the ideXlab platform.
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cloning and characterization of the streptomyces peucetius dnmzuv genes encoding three enzymes required for biosynthesis of the daunorubicin precursor thymidine diphospho l Daunosamine
Journal of Bacteriology, 1997Co-Authors: Sharee Otten, Krishnamurthy Madduri, Mark Gallo, C R HutchinsonAbstract:Characterization of the dnmZ, dnmU, and dnmV genes from the daunorubicin-producer Streptomyces peucetius by DNA sequence analysis indicated that these genes encode a protein of unknown function plus a putative thymidine diphospho-4-keto-6-deoxyglucose-3(5)-epimerase and thymidine diphospho-4-ketodeoxyhexulose reductase, respectively. Inactivation of each of the three genes by gene disruption and replacement in the wild-type strain demonstrated that all of them are required for Daunosamine biosynthesis.
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enhanced antibiotic production by manipulation of the streptomyces peucetius dnrh and dnmt genes involved in doxorubicin adriamycin biosynthesis
Journal of Bacteriology, 1996Co-Authors: C Scotti, C R HutchinsonAbstract:Sequence analysis of a 3.4-kb region Streptomyces peucetius daunorubicin (DNR) gene cluster established the presence of the dnrH and dnmT genes. In dnrH mutants, DNR production increased 8.5-fold, compared with that in the wild-type strain, while dnmT mutants accumulated epsilon-rhodomycinone (RHO), which normally becomes glycosylated in daunorubicin biosynthesis. Hence, dnmT may be involved in the biosynthesis or attachment of Daunosamine to RHO or in the regulation of this process. Since the DnrH protein is similar to known glycosyl transferases, this protein may catalyze the conversion of DNR to its polyglycosylated forms, known as baumycins. Overexpression of dnmT in the wild-type and dnrH mutant strains resulted in a major decrease in RHO accumulation and increase in DNR production.
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the dnrm gene in streptomyces peucetius contains a naturally occurring frameshift mutation that is suppressed by another locus outside of the daunorubicin production gene cluster
Microbiology, 1996Co-Authors: Mark Gallo, Joanne Ward, C R HutchinsonAbstract:Summary: A 2.7 kb BamHI fragment of the daunorubicin biosynthetic cluster in Streptomyces peucetius ATCC 29050 was shown to contain two ORFs, dnrL and dnrM, whose deduced products exhibit a high sequence similarity to a number of glucose-1-phosphate thymidylyl transferases and TDP-D-glucose dehydratases, respectively. Although these genes were believed to be necessary for the synthesis of the deoxyaminosugar, Daunosamine, a constituent of daunorubicin, the dnrM gene contains a frameshift in the DNA sequence that causes the premature termination of translation. A gene encoding another TDP-glucose 4,6-dehydratase, previously isolated from S. peucetius, was identified by PCR amplification of genomic DNA. The presence of this gene explains why a dnrM::aphll mutation did not block daunorubicin production.
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cloning and characterization of the streptomyces peucetius dnrqs genes encoding a Daunosamine biosynthesis enzyme and a glycosyl transferase involved in daunorubicin biosynthesis
Journal of Bacteriology, 1995Co-Authors: Sharee Otten, J. Ferguson, C R HutchinsonAbstract:The dnrQS genes from the daunorubicin producer Streptomyces peucetius were characterized by DNA sequencing, complementation analysis, and gene disruption. The dnrQ gene is required for Daunosamine biosynthesis, and dnrS appears to encode a glycosyltransferase for the addition of the 2,3,6-trideoxy-3-aminohexose, Daunosamine, to epsilon-rhodomycinone.
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functional characterization and transcriptional analysis of the dnrr1 locus which controls daunorubicin biosynthesis in streptomyces peucetius
Journal of Bacteriology, 1995Co-Authors: Krishnamurthy Madduri, C R HutchinsonAbstract:: We previously proposed that the adjacent dnrIJ genes represent a two-component regulatory system controlling daunorubicin biosynthesis in Streptomyces peucetius on the basis of the homology of the DnrI and DnrJ proteins to other response regulator proteins and the effect of a dnrI::aphII mutation. In the present paper we report the results of work with the dnrI::aphII mutant in complementation, bioconversion, and transcriptional analysis experiments to understand the function of dnrI. For five putative operons in the sequenced portion of the S. peucetius daunorubicin biosynthesis gene cluster examined, all of the potential transcripts are present in the delta dnrJ mutant and wild-type strains but absent in the dnrI::aphII strain. Since these transcripts code for both early- and late-acting enzymes in daunorubicin biosynthesis, dnrI seems to control all of the daunorubicin biosynthesis genes directly or indirectly. Transcriptional mapping of the 5' and 3' ends of the dnrIJ transcript and the termination site of the convergently transcribed dnrZUV transcript reveals, interestingly, that the two transcripts share extensive complementarity in the regions coding for daunorubicin biosynthesis enzymes. In addition, dnrI may regulate the expression of the drrAB and drrC daunorubicin resistance genes. The delta dnrJ mutant accumulates epsilon-rhodomycinone, the aglycone precursor of daunorubicin. Since this mutant contains transcripts coding for several early- and late-acting enzymes and since dnr mutants blocked in deoxysugar biosynthesis accumulate epsilon-rhodomycinone, we conclude that dnrJ is a Daunosamine biosynthesis gene. Moreover, newly available gene sequence data show that the DnrJ protein resembles a group of putative aminotransferase enzymes, suggesting that the role of DnrJ is to add an amino group to an intermediate of Daunosamine biosynthesis.
Jun Kino - One of the best experts on this subject based on the ideXlab platform.
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synthesis of n bz protected d Daunosamine and d ristosamine by silica gel promoted intramolecular conjugate addition of trichloroacetimidates obtained from osmundalactone and its epimer
European Journal of Organic Chemistry, 2010Co-Authors: Yoshitaka Matsushima, Jun KinoAbstract:Trichloroacetimidates prepared from osmundalactone and its epimer unexpectedly undergo intramolecular conjugate addition during silica gel chromatography to produce oxazolines in excellent yields. The novel, simple synthesis of N-Bz-protected D-Daunosamine and D-ristosamine from these oxazolines is described in this paper.
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an intramolecular conjugate addition of γ trichloroacetimidoyloxy α β unsaturated esters a very concise route to Daunosamine acosamine ristosamine and 3 epi Daunosamine precursors
Tetrahedron Letters, 2006Co-Authors: Yoshitaka Matsushima, Jun KinoAbstract:A new and very concise strategy has been formulated for the synthesis of 3-amino-2,3,6-trideoxyhexoses, Daunosamine, acosamine, ristosamine and 3-epi-Daunosamine, via cis- and trans-oxazoline intermediates assembled by a novel intramolecular conjugate addition of γ-trichloroacetimidoyloxy-α,β-unsaturated esters in an acyclic system.
Gurmit S Gill - One of the best experts on this subject based on the ideXlab platform.
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a stereoselective synthesis of 6 6 6 trifluoro l Daunosamine and 6 6 6 trifluoro l acosamine
Organic and Biomolecular Chemistry, 2006Co-Authors: Colin M Hayman, David S Larsen, Jim Simpson, Karl B Bailey, Gurmit S GillAbstract:A short synthesis of 6,6,6-trifluoro-L-acosamine 15 and 6,6,6-trifluoro-L-Daunosamine 19 has been accomplished. The pyranose ring system of these carbohydrate analogues was formed by a hetero-Diels–Alder reaction of vinylogous imide 11 and ethyl vinyl ether which gave adduct 12a in 40% yield. Hydroboration gave 13 and subsequent hydrogenolytic removal of the (R)-2-phenylethyl chiral auxiliary gave ethyl 6,6,6-trifluoro-L-acosaminide 14. Acid hydrolysis furnished target 15. Glycoside 13 was N-trifluoroacetylated to give 16, the structure was confirmed by single crystal X-ray diffraction. The C-4 stereochemistry of 16 was inverted by Swern oxidation of the 4-OH group, and subsequent borohydride reduction to give 17. Hydrogenolytic removal of the auxiliary gave ethyl-6,6,6-trifluoro-L-daunosaminide 18. Acid hydrolysis provided 19.
Jae Kyung Sohng - One of the best experts on this subject based on the ideXlab platform.
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exploration of two epimerase homologs in streptomyces peucetius atcc 27952
Applied Microbiology and Biotechnology, 2013Co-Authors: Bijay Singh, Taejin Oh, Jae Kyung SohngAbstract:Streptomyces peucetius ATCC 27952 is a potent producer of the therapeutically important antitumor drug, doxorubicin. S. peucetius contains two deoxythymidine diphospho (dTDP)-4-keto-6-deoxyglucose 3,5-epimerase-encoding genes, dnmU and rmbC, in its genome. While dnmU from the doxorubicin biosynthesis gene cluster is involved in the biosynthesis of dTDP-l-Daunosamine, rmbC is involved in the biosynthesis of dTDP-l-rhamnose, a precursor of cell wall biosynthesis. The proteins encoded by dnmU and rmbC share 47 % identity and 64 % similarity with each other. Both enzymes converted the same substrate, dTDP-4-keto-6-deoxy-d-glucose, into dTDP-4-keto-l-rhamnose in vitro. However, when disruption of dnmU or rmbC was carried out, neither gene in S. peucetius compensated for each other’s loss of function in vivo. These results demonstrated that although dnmU and rmbC encode for similar functional proteins, their native roles in their respective biosynthetic pathways in vivo are specific and independent of one other. Moreover, the disruption of rmbC resulted in fragmented mycelia that quickly converted into gray pigmented spores. Additionally, the production of doxorubicin, a major product of S. peucetius, appeared to be abolished after the disruption of rmbC, demonstrating its pleiotropic effect. This adverse effect might have switched on the genes encoding for spore formation, arresting the expression of many genes and, thereby, preventing the production of other metabolites.
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Development of a Streptomyces venezuelae-Based Combinatorial Biosynthetic System for the Production of Glycosylated Derivatives of Doxorubicin and Its Biosynthetic Intermediates
Applied and environmental microbiology, 2011Co-Authors: Ah Reum Han, Je Won Park, Jae Kyung Sohng, Eunji Kim, Mi Kyeong Lee, Yeon Hee Ban, Young Ji Yoo, Byung-gee Kim, Yeo Joon YoonAbstract:Doxorubicin, one of the most widely used anticancer drugs, is composed of a tetracyclic polyketide aglycone and l-Daunosamine as a deoxysugar moiety, which acts as an important determinant of its biological activity. This is exemplified by the fewer side effects of semisynthetic epirubicin (4'-epi-doxorubicin). An efficient combinatorial biosynthetic system that can convert the exogenous aglycone ε-rhodomycinone into diverse glycosylated derivatives of doxorubicin or its biosynthetic intermediates, rhodomycin D and daunorubicin, was developed through the use of Streptomyces venezuelae mutants carrying plasmids that direct the biosynthesis of different nucleotide deoxysugars and their transfer onto aglycone, as well as the postglycosylation modifications. This system improved epirubicin production from ε-rhodomycinone by selecting a substrate flexible glycosyltransferase, AknS, which was able to transfer the unnatural sugar donors and a TDP-4-ketohexose reductase, AvrE, which efficiently supported the biosynthesis of TDP-4-epi-l-Daunosamine. Furthermore, a range of doxorubicin analogs containing diverse deoxysugar moieties, seven of which are novel rhodomycin D derivatives, were generated. This provides new insights into the functions of deoxysugar biosynthetic enzymes and demonstrates the potential of the S. venezuelae-based combinatorial biosynthetic system as a simple biological tool for modifying structurally complex sugar moieties attached to anthracyclines as an alternative to chemical syntheses for improving anticancer agents.
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precursor for biosynthesis of sugar moiety of doxorubicin depends on rhamnose biosynthetic pathway in streptomyces peucetius atcc 27952
Applied Microbiology and Biotechnology, 2010Co-Authors: Bijay Singh, Jae Kyung SohngAbstract:The doxorubicin biosynthetic gene cluster in Streptomyces peucetius ATCC 27952 contains a TDP-D-glucose 4,6-dehydratase gene, dnmM, that is putatively involved in the biosynthesis of Daunosamine, but the gene contains a frameshift in the DNA sequence that would cause premature termination of translation. In pursuit of another TDP-D-glucose 4,6-dehydratase in S. peucetius, a homologue gene, rmbB, was found, whose deduced product exhibits high sequence similarity to a number of TDP-D-glucose 4,6-dehydratases. The gene was located within a putative rhamnose biosynthetic gene cluster at another locus in the genome. RmbB was verified to be a functional TDP-D-glucose 4,6-dehydratase by enzyme assay as it catalyzed the conversion of TDP-D-glucose into TDP-4-keto-6-deoxy-D-glucose. Inactivation of rmbB in the S. peucetius genome abolished the production of doxorubicin while complementation of the same gene in an rmbB knockout mutant restored the doxorubicin production. Hence, rmbB provides TDP-4-keto-6-deoxy-D-glucose as a nucleotide sugar precursor for the biosynthesis of doxorubicin.
Yoshitaka Matsushima - One of the best experts on this subject based on the ideXlab platform.
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synthesis of n bz protected d Daunosamine and d ristosamine by silica gel promoted intramolecular conjugate addition of trichloroacetimidates obtained from osmundalactone and its epimer
European Journal of Organic Chemistry, 2010Co-Authors: Yoshitaka Matsushima, Jun KinoAbstract:Trichloroacetimidates prepared from osmundalactone and its epimer unexpectedly undergo intramolecular conjugate addition during silica gel chromatography to produce oxazolines in excellent yields. The novel, simple synthesis of N-Bz-protected D-Daunosamine and D-ristosamine from these oxazolines is described in this paper.
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an intramolecular conjugate addition of γ trichloroacetimidoyloxy α β unsaturated esters a very concise route to Daunosamine acosamine ristosamine and 3 epi Daunosamine precursors
Tetrahedron Letters, 2006Co-Authors: Yoshitaka Matsushima, Jun KinoAbstract:A new and very concise strategy has been formulated for the synthesis of 3-amino-2,3,6-trideoxyhexoses, Daunosamine, acosamine, ristosamine and 3-epi-Daunosamine, via cis- and trans-oxazoline intermediates assembled by a novel intramolecular conjugate addition of γ-trichloroacetimidoyloxy-α,β-unsaturated esters in an acyclic system.
