Microcin PDI regulation and proteolytic cleavage are unique among known microcins

• DOI: 10.1038/srep42529
• Publication Date: 2017-02-16T10:34:09Z
• Authors: Zhe Zhao; Lisa H. Orfe; Jinxin Liu; Shao-Yeh Lu; Thomas E. Besser; Douglas R. Call
• Keywords: Cleavage (geology); Site-directed mutagenesis

Abstract Microcin PDI inhibits a diversity of pathogenic Escherichia coli through the action an effector protein, McpM. In this study we demonstrated that expression inhibitory phenotype is induced under low osmolarity conditions and primarily controlled by EnvZ/OmpR two-component regulatory system. Functional, mutagenesis complementation experiments were used to empirically demonstrate EnvZ required for regulation mcpM dependent on binding phosphorylated OmpR promoter region. The may recognize three different sites within Site-directed revealed McpM precursor peptide includes two leader peptides undergo sequential cleavage at positions G17/G18 G35/A36 during export type I secretion Competition assays showed both cleaved products are although could not distinguish loss function from in these assays. has four cysteines mature site-directed first necessary inhibit susceptible cells. Together data combined with previous work indicate MccPDI unique amongst microcins have been described date.