title: Knockout of the gene (ste15) encoding a glycosyltransferase and its function in biosynthesis of exopolysaccharide in Streptomyces sp. 139.
abstract: Streptomyces sp. 139 produces a novel exopolysaccharide (EPS) designated Ebosin which has antagonistic activity for IL-1R in vitro and remarkable anti-rheumatic arthritis activity in vivo. We previously identified a ste (Streptomyces eps) gene cluster consisting of 27 ORFs responsible for Ebosin biosynthesis. The gene product of ste15 shows high homology to known glycosyltransferases (GTFs). To elucidate its function in Ebosin biosynthesis, the ste15 gene was knocked out with a double crossover via homologous recombination. Our analysis of monosaccharide composition for EPS-m produced by the mutant strain Streptomyces sp. 139 (ste15(-)) showed that glucose was significantly diminished compared to its natural counterpart Ebosin. This derivative of Ebosin lost the antagonistic activity for IL-1R in vitro and its molecular mass was smaller than Ebosin. These results have demonstrated that the ste15 gene codes for a GTF for glucose, which is functionally involved in Ebosin biosynthesis.
authors.affiliation: Institute of Medicinal Biotechnology, Tian Tan, 100050 Beijing, China.
authors.forename: Qing-Li
authors.initials: QL
authors.lastname: Sun
authors.forename: Ling-Yan
authors.initials: LY
authors.lastname: Wang
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Shan
authors.forename: Rong
authors.initials: R
authors.lastname: Jiang
authors.forename: Lian-Hong
authors.initials: LH
authors.lastname: Guo
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ren
authors.initials: R
authors.lastname: Zhang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D008401:Gas Chromatography-Mass Spectrometry; D017353:Gene Deletion; D005816:Genetic Complementation Test; D016695:Glycosyltransferases / Q000235:genetics*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009005:Monosaccharides / Q000032:analysis; D016254:Mutagenesis, Insertional; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis* / Q000737:chemistry / Q000276:immunology; D017472:Receptors, Interleukin-1 / Q000037:antagonists & inhibitors; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D009005:Monosaccharides; D011135:Polysaccharides, Bacterial; D017472:Receptors, Interleukin-1; D016695:Glycosyltransferases