Phospholipid-independent biogenesis of a functional RP4 conjugation pilus.

ABSTRACT: Conjugation, the process of DNA transfer between bacteria, is initiated universally by the formation of a mating pair formation (MPF) via a conjugative pilus. Conjugation of the IncP RP4 plasmid is mediated by short, non-retractable, rigid mating pili. Here, we report the cryo-EM structure of the RP4 pilus at 2.75 Å resolution. Uniquely, and consistently with quantitative mass spectral analysis, this revealed that the cyclic TrbC pilin subunit is not lipidated. Consistently, an E. coli pgsA mutant lacking phosphatidylglycerol (PG) can serve as a donor of RP4 but not of R27, encoding the H-pilus consisting of PG-associated cyclic pilin subunits (TrhA). The RP4 is the first example of a lipid-independent functional mating pilus. This discovery not only challenges the long-held assumpt

SUBMITTER: Ishimoto N 

PROVIDER: S-EPMC12637531 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature