1z9s
From Proteopedia
Crystal Structure of the native chaperone:subunit:subunit Caf1M:Caf1:Caf1 complex
Structural highlights
FunctionCAF1M_YERPE Has a stimulatory role for the envelope antigen F1 secretion. It seems to interact with the subunit polypeptide and to prevent it from digestion by a protease. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPeriplasmic chaperone/usher machineries are used for assembly of filamentous adhesion organelles of Gram-negative pathogens in a process that has been suggested to be driven by folding energy. Structures of mutant chaperone-subunit complexes revealed a final folding transition (condensation of the subunit hydrophobic core) on the release of organelle subunit from the chaperone-subunit pre-assembly complex and incorporation into the final fibre structure. However, in view of the large interface between chaperone and subunit in the pre-assembly complex and the reported stability of this complex, it is difficult to understand how final folding could release sufficient energy to drive assembly. In the present paper, we show the X-ray structure for a native chaperone-fibre complex that, together with thermodynamic data, shows that the final folding step is indeed an essential component of the assembly process. We show that completion of the hydrophobic core and incorporation into the fibre results in an exceptionally stable module, whereas the chaperone-subunit pre-assembly complex is greatly destabilized by the high-energy conformation of the bound subunit. This difference in stabilities creates a free energy potential that drives fibre formation. Resolving the energy paradox of chaperone/usher-mediated fibre assembly.,Zavialov AV, Tischenko VM, Fooks LJ, Brandsdal BO, Aqvist J, Zav'yalov VP, Macintyre S, Knight SD Biochem J. 2005 Aug 1;389(Pt 3):685-94. PMID:15799718[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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