Biosynthesis of the Carbamoylated D-Gulosamine Moiety of Streptothricins: Involvement of a Guanidino-N-glycosyltransferase and an N-Acetyl-D-gulosamine Deacetylase----中国科学院微生物研究所

科研成果

论文题目:	Biosynthesis of the Carbamoylated D-Gulosamine Moiety of Streptothricins: Involvement of a Guanidino-N-glycosyltransferase and an N-Acetyl-D-gulosamine Deacetylase
作者:	Guo Zhengyan# Li Jine#, Qin Hua#, Wang Min, Lv Xun, Li Xuebing, Chen Yihua*.
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刊物名称:	Angew Chem Int Ed Engl
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年份:	2015
影响因子:	12.06
论文下载:	http://onlinelibrary.wiley.com/doi/10.1002/anie.201412190/abstract;jsessionid=F127F17B01202BF5340F4AB0AEC70EE5.f02t02
摘要:	Streptothricins (STNs) are atypical aminoglycosides containing a rare carbamoylated D-gulosamine (D-GulN) moiety, and the antimicrobial activity of STNs has been exploited for crop protection. Herein, the biosynthetic pathway of the carbamoylated D-GulN moiety was delineated. An N-acetyl-D-galactosamine is first attached to the streptolidine lactam by the glycosyltransferse StnG and then epimerized to N-acetyl-D-gulosamine by the putative epimerase StnJ. After carbamoylation by the carbamoyltransferase StnQ, N-acetyl-D-GulN is deacetylated by StnI to furnish the carbamoylated D-GulN moiety. In vitro studies characterized two novel enzymes: StnG is an unprecedented GT-A fold N-glycosyltransferase that glycosylates the imine nitrogen atom of guanidine, and StnI is the first reported N-acetyl-D-GulN deacetylase.