title: Structure of the GspK-GspI-GspJ complex from the enterotoxigenic Escherichia coli type 2 secretion system.
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 alpha-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.
authors.affiliation: Department of Biochemistry, Biomolecular Structure Center, University of Washington, Box 357742, Seattle, Washington 98195, USA.
authors.forename: Konstantin V
authors.initials: KV
authors.lastname: Korotkov
authors.forename: Wim G J
authors.initials: WG
authors.lastname: Hol
mesh_terms: D018360:Crystallography, X-Ray; D054307:Enterotoxigenic Escherichia coli / Q000737:chemistry / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D046912:Multiprotein Complexes / Q000737:chemistry / Q000378:metabolism; D017434:Protein Structure, Tertiary
chemical_list: D029968:Escherichia coli Proteins; C529110:GspI protein, E coli; C529111:GspJ protein, E coli; C529109:GspK protein, E coli; D046912:Multiprotein Complexes