Journal
JOURNAL OF MOLECULAR BIOLOGY
Volume 398, Issue 1, Pages 111-121Publisher
ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
DOI: 10.1016/j.jmb.2010.03.006
Keywords
CbpA-J domain; CbpM; NMR structure; site-directed mutagenesis; SPR
Categories
Funding
- CIHR
Ask authors/readers for more resources
CbpA, one of the Escherichia coli DnaJ homologues, acts as a co-chaperone in the DnaK chaperone system. Despite its extensive similarity in domain structure and function to DnaJ, CbpA has a unique and specific regulatory mechanism mediated through the small protein CbpM. Both CbpA and CbpM are highly conserved in bacteria. Earlier studies showed that CbpM interacts with the N-terminal J-domain of CbpA inhibiting its co-chaperone activity but the structural basis of this interaction is not known. Here, we have combined NMR spectroscopy, site-directed mutagenesis and surface plasmon resonance to characterize the CbpA/CbpM interaction at the molecular level. We have determined the solution structure of the CbpA J-domain and mapped the residues that are perturbed upon CbpM binding. The NMR data defined a broad region on helices alpha 2 and alpha 3 as involved in the interactions. Site-directed mutagenesis has been used to further delineate the CbpA J-domain/CbpM interface. We show that the binding sites of CbpM and DnaK on CbpA J-domain overlap, which suggests a competition between DnaK and CbpM for binding to CbpA as a mechanism for CbpA regulation. This study also provides the explanation for the specificity of CbpM for CbpA versus DnaJ, by identifying the key residues for differential binding. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available