TraG-like proteins of type IV secretion systems: functional dissection of the multiple activities of TraG (RP4) and TrwB (R388).

ABSTRACT: TraG-like proteins are essential components of type IV secretion systems. During secretion, TraG is thought to translocate defined substrates through the inner cell membrane. The energy for this transport is presumably delivered by its potential nucleotide hydrolase (NTPase) activity. TraG of conjugative plasmid RP4 is a membrane-anchored oligomer that binds RP4 relaxase and DNA. TrwB (R388) is a hexameric TraG-like protein that binds ATP. Both proteins, however, lack NTPase activity under in vitro conditions. We characterized derivatives of TraG and TrwB truncated by the N-terminal membrane anchor (TraGdelta2 and TrwBdelta1) and/or containing a point mutation at the putative nucleotide-binding site (TraGdelta2K187T and TraGK187T). Unlike TraG and TrwB, truncated derivatives behaved as mon

SUBMITTER: Schroder G 

PROVIDER: S-EPMC165781 | biostudies-literature | 2003 Aug

REPOSITORIES: biostudies-literature