Characterization of the interaction between the Salmonella type III secretion system tip protein SipD and the needle protein PrgI by paramagnetic relaxation enhancement.

ABSTRACT: Many Gram-negative bacteria that cause major diseases and mortality worldwide require the type III secretion system (T3SS) to inject virulence proteins into their hosts and cause infections. A structural component of the T3SS is the needle apparatus, which consists of a base, an external needle, and a tip complex. In Salmonella typhimurium, the external needle is assembled by the polymerization of the needle protein PrgI. On top of this needle sits a tip complex, which is partly formed by the tip protein SipD. How SipD interacts with PrgI during the assembly of the T3SS needle apparatus remains unknown. The central region of PrgI forms an α-helical hairpin, whereas SipD has a long central coiled-coil, which is a defining structural feature of other T3SS tip proteins as well. Using NMR para

SUBMITTER: Rathinavelan T 

PROVIDER: S-EPMC3039345 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature