PT  - JOURNAL ARTICLE
AU  - Zhu, Xiaotian
AU  - Zhao, Xun
AU  - Burkholder, William F.
AU  - Gragerov, Alexander
AU  - Ogata, Craig M.
AU  - Gottesman, Max E.
AU  - Hendrickson, Wayne A.
TI  - Structural Analysis of Substrate Binding by the Molecular Chaperone DnaK
AID  - 10.1126/science.272.5268.1606
DP  - 1996 Jun 14
TA  - Science
PG  - 1606--1614
VI  - 272
IP  - 5268
4099  - http://science.sciencemag.org/content/272/5268/1606.short
4100  - http://science.sciencemag.org/content/272/5268/1606.full
SO  - Science1996 Jun 14; 272
AB  - 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 Å resolution. The structure consists of a β-sandwich subdomain followed by α-helical segments. The peptide is bound to DnaK in an extended conformation through a channel defined by loops from the β sandwich. An α-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.