Structure of the Yersinia enterocolitica type III secretion translocator chaperone SycD.
Cast your vote
You can rate an item by clicking the amount of stars they wish to award to this item.
When enough users have cast their vote on this item, the average rating will also be shown.
Your vote was cast
Thank you for your feedback
Thank you for your feedback
MetadataShow full item record
AbstractMany Gram-negative bacteria use a type III secretion (T3S) system to directly inject effector molecules into eucaryotic cells in order to establish a symbiotic or pathogenic relationship with their host. The translocation of many T3S proteins requires specialized chaperones from the bacterial cytosol. SycD belongs to a class of T3S chaperones that assists the secretion of pore-forming translocators and, specifically chaperones the translocators YopB and YopD from enteropathogenic Yersinia enterocolitica. In addition, SycD is involved in the regulation of virulence factor biosynthesis and secretion. In this study, we present two crystal structures of Y. enterocolitica SycD at 1.95 and 2.6 A resolution, the first experimental structures of a T3S class II chaperone specific for translocators. The fold of SycD is entirely alpha-helical and reveals three tetratricopeptide repeat-like motifs that had been predicted from amino acid sequence. In both structures, SycD forms dimers utilizing residues from the first tetratricopeptide repeat motif. Using site-directed mutagenesis and size exclusion chromatography, we verified that SycD forms head-to-head homodimers in solution. Although in both structures, dimerization largely depends on the same residues, the two assemblies represent alternative dimers that exhibit different monomer orientations and overall shape. In these two distinct head-to-head dimers, both the concave and the convex surface of each monomer are accessible for interactions with the SycD binding partners YopB and YopD. A SycD variant carrying two point mutations in the dimerization interface is properly folded but defective in dimerization. Expression of this stable SycD monomer in Yersinia does not rescue the phenotype of a sycD null mutant, suggesting a physiological relevance of the dimerization interface.
CitationStructure of the Yersinia enterocolitica type III secretion translocator chaperone SycD. 2008, 375 (4):997-1012 J. Mol. Biol.
AffiliationDivision of Structural Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, D-38124 Braunschweig, Germany.
JournalJournal of molecular biology
The following license files are associated with this item:
- Yersinia enterocolitica type III secretion chaperone SycD: recombinant expression, purification and characterization of a homodimer.
- Authors: Schmid A, Dittmann S, Grimminger V, Walter S, Heesemann J, Wilharm G
- Issue date: 2006 Oct
- Crystal structure of the Yersinia enterocolitica type III secretion chaperone SycD in complex with a peptide of the minor translocator YopD.
- Authors: Schreiner M, Niemann HH
- Issue date: 2012 Jun 18
- Yersinia pestis YopD 150-287 fragment is partially unfolded in the native state.
- Authors: Raab R, Swietnicki W
- Issue date: 2008 Mar
- Role of SycD, the chaperone of the Yersinia Yop translocators YopB and YopD.
- Authors: Neyt C, Cornelis GR
- Issue date: 1999 Jan
- Structural and biochemical characterization of the type III secretion chaperones CesT and SigE.
- Authors: Luo Y, Bertero MG, Frey EA, Pfuetzner RA, Wenk MR, Creagh L, Marcus SL, Lim D, Sicheri F, Kay C, Haynes C, Finlay BB, Strynadka NC
- Issue date: 2001 Dec