Antibacterial toxin colicin N and phage protein G3p compete with TolB for a binding site on TolA.

ABSTRACT: Most colicins kill Escherichia coli cells by membrane pore formation or nuclease activity and, superficially, the mechanisms are similar: receptor binding, translocon recruitment, periplasmic receptor binding and membrane insertion. However, in detail, they employ a wide variety of molecular interactions that reveal a high degree of evolutionary diversification. Group A colicins bind to members of the TolQRAB complex in the periplasm and heterotrimeric complexes of colicin-TolA-TolB have been observed for both ColA and ColE9. ColN, the smallest and simplest pore-forming colicin, binds only to TolA and we show here that it uses the binding site normally used by TolB, effectively preventing formation of the larger complex used by other colicins. ColN binding to TolA was by β-strand addition

SUBMITTER: Ridley H 

PROVIDER: S-EPMC4339652 | biostudies-literature | 2015 Mar

REPOSITORIES: biostudies-literature