biostudies-literatureKorotkov KVNCRR NIH HHSNIAID NIH HHSe1002228https://www.ebi.ac.uk/biostudies/studies/S-EPMC3169554biostudies-literatureUnknown7(9)Type II secretion systems (T2SSs) are critical for secretion of many proteins from Gram-negative bacteria. In the T2SS, the outer membrane secretin GspD forms a multimeric pore for translocation of secreted proteins. GspD and the inner membrane protein GspC interact with each other via periplasmic domains. Three different crystal structures of the homology region domain of GspC (GspC(HR)) in complex with either two or three domains of the N-terminal region of GspD from enterotoxigenic Escherichia coli show that GspC(HR) adopts an all-β topology. N-terminal β-strands of GspC and the N0 domain of GspD are major components of the interface between these inner and outer membrane proteins from the T2SS. The biological relevance of the observed GspC-GspD interface is shown by analysis of variantPLoS pathogensStructural and functional studies on the interaction of GspC and GspD in the type II secretion system.PMC3169554AI34501R01 AI034501R56 AI049294AI31940AI049294R56 AI034501R01 AI049294P41RR001209R01 AI031940P41 RR001209Steyaert JHol WGJobling MGSandkvist MPruneda JHolmes RKTurley SJohnson TLHeroux AKorotkov KVPardon EfalseStructural and functional studies on the interaction of GspC and GspD in the type II secretion system.Type II secretion systems (T2SSs) are critical for secretion of many proteins from Gram-negative bacteria. In the T2SS, the outer membrane secretin GspD forms a multimeric pore for translocation of secreted proteins. GspD and the inner membrane protein GspC interact with each other via periplasmic domains. Three different crystal structures of the homology region domain of GspC (GspC(HR)) in complex with either two or three domains of the N-terminal region of GspD from enterotoxigenic Escherichia coli show that GspC(HR) adopts an all-β topology. N-terminal β-strands of GspC and the N0 domain of GspD are major components of the interface between these inner and outer membrane proteins from the T2SS. The biological relevance of the observed GspC-GspD interface is shown by analysis of variant2011-01-01T00:00:00Z2011 Sep2026-04-08T01:36:12.721Z2025-07-01T03:05:25.816ZS-EPMC31695542193154810.1371/journal.ppat.1002228