1R6Q

ClpNS with fragments

Summary for 1R6Q

• Entry DOI: 10.2210/pdb1r6q/pdb
• Related: 1MBU 1R6C 1R6O
• Descriptor: ATP-dependent Clp protease ATP-binding subunit clpA, ATP-dependent Clp protease adaptor protein clpS, BIS-(2-HYDROXYETHYL)AMINO-TRIS(HYDROXYMETHYL)METHANE YTTRIUM, ... (6 entities in total)
• Functional Keywords: clpa, aaa+, n-terminal domain, clps, crystal, binding mechanism, chaperone-protein binding complex, chaperone/protein binding
• Biological source: Escherichia coli; More
• Total number of polymer chains: 4
• Total formula weight: 58341.20

Authors

Xia, D.,Maurizi, M.R.,Guo, F.,Singh, S.K.,Esser, L. (deposition date: 2003-10-16, release date: 2005-02-15, Last modification date: 2023-08-23)

Primary citation

Xia, D.,Esser, L.,Singh, S.K.,Guo, F.,Maurizi, M.R.
Crystallographic investigation of peptide binding sites in the N-domain of the ClpA chaperone.
J.Struct.Biol., 146:166-179, 2004

PubMed Abstract: Escherichia coli ClpA, an Hsp100/Clp chaperone and an integral component of the ATP-dependent ClpAP protease, participates in the dissolution and degradation of regulatory proteins and protein aggregates. ClpA consists of three functional domains: an N-terminal domain and two ATPase domains, D1 and D2. The N-domain is attached to D1 by a mobile linker and is made up of two tightly bound, identically folded alpha-helical bundles related by a pseudo 2-fold symmetry. Between the halves of the pseudo-dimer is a large flexible acidic loop that becomes better ordered upon binding of the small adaptor protein, ClpS. We have identified a number of structural features in the N-domain, including a Zn(++) binding motif, several interfaces for binding to ClpS, and a prominent hydrophobic surface area that binds peptides in different configurations. These structural motifs may contribute to binding of protein or peptide substrates with weak affinity and broad specificity. Kinetic studies comparing wild-type ClpA to a mutant ClpA with its N-domain deleted show that the N-domains contribute to the binding of a non-specific protein substrate but not of a folded substrate with the specific SsrA recognition tag. A functional model is proposed in which the N-domains in ClpA function as tentacles to weakly hold on to proteins thereby enhancing local substrate concentration.

PubMed: 15037248
DOI: 10.1016/j.jsb.2003.11.025

Experimental method

X-RAY DIFFRACTION (2.35 Å)