Biosynthesis of the Carbamoylated<scp>D</scp>-Gulosamine Moiety of Streptothricins: Involvement of a Guanidino-<i>N</i>-glycosyltransferase and an<i>N</i>-Acetyl-<scp>D</scp>-gulosamine Deacetylase
作者:Zhengyan Guo、Jine Li、Hua Qin、Min Wang、Xun Lv、Xuebing Li、Yihua Chen
DOI:10.1002/anie.201412190
日期:2015.4.20
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
链霉菌素(STNs)是一种非典型的氨基糖苷类,含有罕见的氨基甲酰化的D-古洛糖胺(D- GulN)部分,STNs的抗菌活性已被用于作物保护。在此,描绘了氨基甲酰化的D- GulN部分的生物合成途径。N-乙酰基-D-半乳糖胺首先通过糖基转移StnG连接到链霉菌内酰胺,然后通过假定的差向异构酶StnJ异构化为N-乙酰基-D-古洛糖胺。通过氨基甲酰基转移酶StnQ进行氨基甲酰基化后,Nst - D - GulN被StnI脱乙酰基,得到氨基甲酰化的D‐GulN部分。体外研究表征了两种新型酶:StnG是前所未有的GT-A折叠N-糖基转移酶,可糖化胍的亚胺氮原子,而StnI是第一个报道的N-乙酰基-D - GulN脱乙酰基酶。