Conjugal plasmid transfer in Streptomyces resembles bacterial chromosome segregation by FtsK/SpoIIIE.

ABSTRACT: Conjugation is a major route of horizontal gene transfer, the driving force in the evolution of bacterial genomes. Antibiotic producing soil bacteria of the genus Streptomyces transfer DNA in a unique process involving a single plasmid-encoded protein TraB and a double-stranded DNA molecule. However, the molecular function of TraB in directing DNA transfer from a donor into a recipient cell is unknown. Here, we show that TraB constitutes a novel conjugation system that is clearly distinguished from DNA transfer by a type IV secretion system. We demonstrate that TraB specifically recognizes and binds to repeated 8 bp motifs on the conjugative plasmid. The specific DNA recognition is mediated by helix α3 of the C-terminal winged-helix-turn-helix domain of TraB. We show that TraB assembles to

SUBMITTER: Vogelmann J 

PROVIDER: S-EPMC3117642 | biostudies-literature | 2011 Jun

REPOSITORIES: biostudies-literature