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The solution structure of the bacterial HSP70 chaperone protein domain DnaK(393–507) in complex with the peptide NRLLLTG
Author(s) -
Stevens Shawn Y.,
Cai Sheng,
Pellecchia Maurizio,
Zuiderweg Erik R.P.
Publication year - 2003
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.03269103
Subject(s) - peptide , chaperone (clinical) , allosteric regulation , protein structure , hsp70 , escherichia coli , protein folding , biophysics , chemistry , crystallography , biology , biochemistry , heat shock protein , enzyme , medicine , pathology , gene
Abstract The Hsp70 family of molecular chaperones participates in a number of cellular processes, including binding to nascent polypeptide chains and assistance in protein (re)folding and degradation. We present the solution structure of the substrate binding domain (residues 393–507) of the Escherichia coli Hsp70, DnaK, that is bound to the peptide NRLLLTG and compare it to the crystal structure of DnaK(389–607) bound to the same peptide. The construct discussed here does not contain the α‐helical domain that characterizes earlier published peptide‐bound structures of the Hsp70s. It is established that removing the α‐helical domain in its entirety does not affect the primary interactions or structure of the DnaK(393–507) in complex with the peptide NRLLLTG. In particular, the arch that protects the substrate‐binding cleft is also formed in the absence of the helical lid. 15 N‐relaxation measurements show that the peptide‐bound form of DnaK(393–507) is relatively rigid. As compared to the peptide‐free state, the peptide‐bound state of the domain shows distinct, widespread, and contiguous differences in structure extending toward areas previously defined as important to the allosteric regulation of the Hsp70 chaperones.