| Title |
Identification of a Methyltransferase Encoded by Gene ste16 and Its Function in Ebosin Biosynthesis of Streptomyces sp. 139 |
| Author |
Hong-Guan Xie1, Yong-Gang Bao1, Li-ping Bai1, Jun-Jie Shan2, Rong Jiang1, Yang Zhang1, Lian-Hong Guo1, Ren Zhang1,3, and Yuan Li1* |
| Address |
1Key Laboratory of Biotechnology of Antibiotics, Ministry of Health, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R. China, 2Institute of Pharmacology and Toxicology, Beijing 100850, P. R. China, 3School of Biological Sciences, University of Wollongong, NSW 2522, Australia |
| Bibliography |
Journal of Microbiology, 47(2),193-200, 2009,
|
| DOI |
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| Key Words |
methyltransferase, ste16, gene disruption, ebosin biosynthesis, Streptomyces |
| Abstract |
Streptomyces sp. 139 generates a novel exopolysaccharide (EPS) designated as Ebosin, which exerts an antagonistic effect on IL-1R in vitro and anti-rheumatic arthritis activity in vivo. A ste gene cluster for Ebosin biosynthesis consisting of 27 ORFs was previously identified in our laboratory. In this paper, ste16 was expressed in Escherichia coli BL21 and the recombinant protein was purified, which has the ability to catalyze the transfer of the methyl group from S-adenosylmethionine (AdoMet) to dTDP-4-keto-6-deoxy-D-glucos, which was thus identified as a methyltransferase. In order to determine the function of ste16 in Ebosin biosynthesis, the gene was disrupted with a double crossover via homologous recombination. The monosaccharide composition of EPS-m generated by the mutant strain Streptomyces sp. 139 (ste16-) was found to differ from that of Ebosin. The IL-1R antagonist activity of EPS-m was markedly lower than that of Ebosin. These experimental results have shown that the ste16 gene codes for a methyltransferase which is involved in Ebosin biosynthesis. |
