molecular chaperone;
Hsp90;
heat shock;
protein folding;
geldanamycin;
D O I:
10.1016/j.jmb.2004.09.055
中图分类号:
Q5 [生物化学];
Q7 [分子生物学];
学科分类号:
071010 ;
081704 ;
摘要:
The ATPase activity of the molecular chaperone Hsp90 is essential for its function in the assembly of client proteins. To understand the mechanism of human Hsp90, we have carried out a detailed kinetic analysis of ATP binding, hydrolysis and product release. ATP binds rapidly in a two-step process involving the formation of a diffusion-collision complex followed by a conformational change. The rate-determining step was shown to be ATP hydrolysis and not subsequent ADP dissociation. There was no evidence from any of the biophysical measurements for cooperativity in either nucleotide binding or hydrolysis for the dimeric protein. A monomeric fragment, lacking the C-terminal dimerisation domain, showed no dependence on protein concentration and, therefore, subunit association for activity. The thermodynamic linkage between client protein binding and nucleotide affinity revealed ATP bound Hsp90 has a higher affinity for client proteins than the ADP bound form. The kinetics are consistent with independent Michaelis-Menten catalysis in each subunit of the Hsp90 dimer. We propose that Hsp90 functions in an open-ring configuration for client protein activation. (C) 2004 Elsevier Ltd. All rights reserved.
机构:Tokyo Metropolitan Inst Med Sci, Dept Cell Biol, Bunkyo Ku, Tokyo 113, Japan
Maruya, M
;
Sameshima, M
论文数: 0引用数: 0
h-index: 0
机构:Tokyo Metropolitan Inst Med Sci, Dept Cell Biol, Bunkyo Ku, Tokyo 113, Japan
Sameshima, M
;
Nemoto, T
论文数: 0引用数: 0
h-index: 0
机构:Tokyo Metropolitan Inst Med Sci, Dept Cell Biol, Bunkyo Ku, Tokyo 113, Japan
Nemoto, T
;
Yahara, I
论文数: 0引用数: 0
h-index: 0
机构:
Tokyo Metropolitan Inst Med Sci, Dept Cell Biol, Bunkyo Ku, Tokyo 113, JapanTokyo Metropolitan Inst Med Sci, Dept Cell Biol, Bunkyo Ku, Tokyo 113, Japan
机构:Tokyo Metropolitan Inst Med Sci, Dept Cell Biol, Bunkyo Ku, Tokyo 113, Japan
Maruya, M
;
Sameshima, M
论文数: 0引用数: 0
h-index: 0
机构:Tokyo Metropolitan Inst Med Sci, Dept Cell Biol, Bunkyo Ku, Tokyo 113, Japan
Sameshima, M
;
Nemoto, T
论文数: 0引用数: 0
h-index: 0
机构:Tokyo Metropolitan Inst Med Sci, Dept Cell Biol, Bunkyo Ku, Tokyo 113, Japan
Nemoto, T
;
Yahara, I
论文数: 0引用数: 0
h-index: 0
机构:
Tokyo Metropolitan Inst Med Sci, Dept Cell Biol, Bunkyo Ku, Tokyo 113, JapanTokyo Metropolitan Inst Med Sci, Dept Cell Biol, Bunkyo Ku, Tokyo 113, Japan