A Major Portion of DNA Gyrase Inhibitor Microcin B17 Undergoes an N,O-Peptidyl Shift during Synthesis

作者：Ghilarov Dmitry; Serebryakova Marina; Shkundina Irina; Severinov Konstantin^*

来源：JOURNAL OF BIOLOGICAL CHEMISTRY, 2011, 286(30): 26308-26318.

DOI：10.1074/jbc.M111.241315

Microcin B17 (McB) is a 43-amino acid antibacterial peptide targeting the DNA gyrase. The McB precursor is ribosomally produced and then post-translationally modified by the Mcb-BCD synthase. Active mature McB contains eight oxazole and thiazole heterocycles. Here, we show that a major portion of mature McB contains an additional unusual modification, a backbone ester bond connecting McB residues 51 and 52. The modification results from an N -> O shift of the Ser(52) residue located immediately downstream of one of McBthiazole heterocycles. We speculate that the N, O-peptidyl shift undergone by Ser(52) is an intermediate of post-translational modification reactions catalyzed by the McbBCD synthase that normally lead to formation of McB heterocycles.

• 出版日期2011-7-29