1ckr

Publication Abstract from PubMed

The three-dimensional structure for the substrate-binding domain of the mammalian chaperone protein Hsc70 of the 70 kDa heat shock class (HSP70) is presented. This domain includes residues 383-540 (18 kDa) and is necessary for the binding of the chaperone with substrate proteins and peptides. The high-resolution NMR solution structure is based on 4150 experimental distance constraints leading to an average root-mean-square precision of 0.38 A for the backbone atoms and 0.76 A for all atoms in the beta-sandwich sub-domain. The protein is observed to bind residue Leu539 in its hydrophobic substrate-binding groove by intramolecular interaction. The position of a helical latch differs dramatically from what is observed in the crystal and solution structures of the homologous prokaryotic chaperone DnaK. In the Hsc70 structure, the helix lies in a hydrophobic groove and is anchored by a buried salt-bridge. Residues involved in this salt-bridge appear to be important for the allosteric functioning of the protein. A mechanism for interdomain allosteric modulation of substrate-binding is proposed. It involves large-scale movements of the helical domain, redefining the location of the hinge area that enables such motions.

High-resolution solution structure of the 18 kDa substrate-binding domain of the mammalian chaperone protein Hsc70.,Morshauser RC, Hu W, Wang H, Pang Y, Flynn GC, Zuiderweg ER J Mol Biol. 1999 Jun 25;289(5):1387-403. PMID:10373374^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.