A noncanonical cytochrome c stimulates calcium binding by PilY1 for type IVa pili formation.

ABSTRACT: Type IVa pili (T4aP) are versatile bacterial cell surface structures that undergo extension/adhesion/retraction cycles powered by the cell envelope-spanning T4aP machine. In this machine, a complex composed of four minor pilins and PilY1 primes T4aP extension and is also present at the pilus tip mediating adhesion. Similar to many several other bacteria, Myxococcus xanthus contains multiple minor pilins/PilY1 sets that are incompletely understood. Here, we report that minor pilins and PilY1 (PilY1.1) of cluster_1 form priming and tip complexes contingent on calcium and a noncanonical cytochrome c (TfcP) with an unusual His/Cys heme ligation. We provide evidence that TfcP is unlikely to participate in electron transport and instead stimulates calcium binding by PilY1.1 at low-

SUBMITTER: Herfurth M 

PROVIDER: S-EPMC8833165 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature