Article abstract
Nature Structural & Molecular Biology 15, 462 - 468 (2008)
Published online: 27 April 2008 | doi:10.1038/nsmb.1426
Structure of the GspK–GspI–GspJ complex from the enterotoxigenic Escherichia coli type 2 secretion system
Konstantin V Korotkov1 & Wim G J Hol1
Abstract
Gram-negative bacteria translocate various proteins including virulence factors across their outer membrane via type 2 secretion systems (T2SSs). T2SSs are thought to contain a pseudopilus, a subcomplex formed by one major and several minor pseudopilins. We report the crystal structure of the complex formed by three minor pseudopilins from enterotoxigenic Escherichia coli. The GspK–GspI–GspJ complex has quasihelical characteristics and an architecture consistent with a localization at the pseudopilus tip. The 
-domain of GspK has a previously unobserved fold with an unexpected dinuclear metal binding site. The area surrounding its disulfide bridge is conserved and might interact with other T2SS components or with secreted proteins.
- Department of Biochemistry, Biomolecular Structure Center, University of Washington, Box 357742, Seattle, Washington 98195, USA.
Correspondence to: Wim G J Hol1 e-mail: wghol@u.washington.edu