Publication Date:
1996-06-14
Description:
DnaK and other members of the 70-kilodalton heat-shock protein (hsp70) family promote protein folding, interaction, and translocation, both constitutively and in response to stress, by binding to unfolded polypeptide segments. These proteins have two functional units: a substrate-binding portion binds the polypeptide, and an adenosine triphosphatase portion facilitates substrate exchange. The crystal structure of a peptide complex with the substrate-binding unit of DnaK has now been determined at 2.0 angstroms resolution. The structure consists of a beta-sandwich subdomain followed by alpha-helical segments. The peptide is bound to DnaK in an extended conformation through a channel defined by loops from the beta sandwich. An alpha-helical domain stabilizes the complex, but does not contact the peptide directly. This domain is rotated in the molecules of a second crystal lattice, which suggests a model of conformation-dependent substrate binding that features a latch mechanism for maintaining long lifetime complexes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhu, X -- Zhao, X -- Burkholder, W F -- Gragerov, A -- Ogata, C M -- Gottesman, M E -- Hendrickson, W A -- GM 34102/GM/NIGMS NIH HHS/ -- GM 37219/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1996 Jun 14;272(5268):1606-14.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Molecular Biophysics, College of Physicians and Surgeons, Columbia University, New York 10032, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8658133" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Binding Sites
;
Chaperonins/chemistry/*metabolism
;
Crystallography, X-Ray
;
Escherichia coli
;
*Escherichia coli Proteins
;
HSP70 Heat-Shock Proteins/chemistry/*metabolism
;
Models, Molecular
;
Molecular Sequence Data
;
Peptides/metabolism
;
Protein Binding
;
Protein Conformation
;
Sequence Homology, Amino Acid
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
