Download MendeleyMolecular Basis for the Unique Role of the Aaa+ Chaperone Clpv in Type Vi Protein Secretion.
Pietrosiuk, A., Lenherr, E.D., Falk, S., Bonemann, G., Kopp, J., Zentgraf, H., Sinning, I., Mogk, A.(2011) J Biol Chem 286: 30010
- PubMed: 21733841
- DOI: https://doi.org/10.1074/jbc.M111.253377
- Primary Citation of Related Structures:
3ZRI, 3ZRJ - PubMed Abstract:
Ring-forming AAA(+) ATPases act in a plethora of cellular processes by remodeling macromolecules. The specificity of individual AAA(+) proteins is achieved by direct or adaptor-mediated association with substrates via distinct recognition domains. We investigated the molecular basis of substrate interaction for Vibrio cholerae ClpV, which disassembles tubular VipA/VipB complexes, an essential step of type VI protein secretion and bacterial virulence. We identified the ClpV recognition site within VipB, showed that productive ClpV-VipB interaction requires the oligomeric state of both proteins, solved the crystal structure of a ClpV N-domain-VipB peptide complex, and verified the interaction surface by mutant analysis. Our results show that the substrate is bound to a hydrophobic groove, which is formed by the addition of a single α-helix to the core N-domain. This helix is absent from homologous N-domains, explaining the unique substrate specificity of ClpV. A limited interaction surface between both proteins accounts for the dramatic increase in binding affinity upon ATP-driven ClpV hexamerization and VipA/VipB tubule assembly by coupling multiple weak interactions. This principle ensures ClpV selectivity toward the VipA/VipB macromolecular complex.
Organizational Affiliation:
Zentrum für Molekulare Biologie Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Universität Heidelberg, Heidelberg, Germany.
