NosN, a Radical <i>S</i>-Adenosylmethionine Methylase, Catalyzes Both C1 Transfer and Formation of the Ester Linkage of the Side-Ring System during the Biosynthesis of Nosiheptide
作者:Joseph W. LaMattina、Bo Wang、Edward D. Badding、Lauren K. Gadsby、Tyler L. Grove、Squire J. Booker
DOI:10.1021/jacs.7b08492
日期:2017.12.6
backbone via ester and thioester linkages, respectively. Herein, we show that NosN, a predicted class C radical S-adenosylmethionine (SAM) methylase, catalyzes both the transfer of a C1 unit from SAM to 3-methylindolic acid linked to Cys8 of a synthetic substrate surrogate as well as the formation of the ester linkage between Glu6 and the nascent C4 methylene moiety of DMIA. In contrast to previous studies
Nosiheptide ,e系列大环硫肽天然产物的成员,包含一个侧环系统,该环系统由3,4-二甲基吲哚酸(DMIA)部分组成,分别通过酯和硫酯键与硫肽主链的Glu6和Cys8连接。在这里,我们显示NosN,一种预测的C类自由基S-腺苷甲硫氨酸(SAM)甲基化酶,催化C1单元从SAM转移到与合成底物Cys8连接的3-甲基吲哚酸,以及它们的形成。 Glu6与DMIA新生的C4亚甲基之间的酯键。与先前的研究表明5'-甲硫基腺苷是该反应的直接甲基供体相反,在我们的研究中,SAM本身起着这种作用,导致S-腺苷同型半胱氨酸作为反应的副产物。