Duquesne Sophie, Destoumieux-Garzón Delphine, Zirah Séverine, Goulard Christophe, Peduzzi Jean, Rebuffat Sylvie
Chimie et Biochimie des Substances Naturelles, UMR 5154 CNRS, Muséum National d'Histoire Naturelle, CP 54, 57 rue Cuvier, 75005 Paris, France.
Chem Biol. 2007 Jul;14(7):793-803. doi: 10.1016/j.chembiol.2007.06.004.
Microcin J25 (MccJ25) is a gene-encoded lasso peptide secreted by Escherichia coli which exerts a potent antibacterial activity by blocking RNA polymerase. Here we demonstrate that McjB and McjC, encoded by genes in the MccJ25 gene cluster, catalyze the maturation of MccJ25. Requirement for both McjB and McjC was shown by gene inactivation and complementation assays. Furthermore, the conversion of the linear precursor McjA into mature MccJ25 was obtained in vitro in the presence of McjB and McjC, all proteins being produced by recombinant expression in E. coli. Analysis of the amino acid sequences revealed that McjB could possess proteolytic activity, whereas McjC would be the ATP/Mg(2+)-dependent enzyme responsible for the formation of the Gly1-Glu8 amide bond. Finally, we show that putative lasso peptides are widespread among Proteobacteria and Actinobacteria.
微菌素J25（MccJ25）是一种由大肠杆菌分泌的基因编码套索肽，它通过阻断RNA聚合酶发挥强大的抗菌活性。在此我们证明，MccJ25基因簇中的基因编码的McjB和McjC催化MccJ25的成熟。基因失活和互补试验表明McjB和McjC都是必需的。此外，在McjB和McjC存在的情况下，体外获得了线性前体McjA向成熟MccJ25的转化，所有蛋白质均通过在大肠杆菌中的重组表达产生。氨基酸序列分析表明，McjB可能具有蛋白水解活性，而McjC将是负责形成Gly1-Glu8酰胺键的ATP/Mg(2+)依赖性酶。最后，我们表明假定的套索肽在变形菌门和放线菌门中广泛存在。
