K+ is an indispensable cofactor for GrpE stimulation of ATPase activity of DnaK·DnaJ complex from Thermus thermophilus

FEBS Letters

Yohda, Masafumi¹  Motohashi, Ken²  Odaka, Masafumi¹  Yoshida, Masasuke² 

[1] The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako-shi, Saitama 351-01, Japan;Research Laboratory of Resources Utilization, R-1, Tokyo Institute of Technology, Nagatsuta 4259, Yokohama 226, Japan

关键词: DnaK;    DnaJ;    GrpE;    Heat-shock protein;    Hsp70;    Molecular chaperone;    Hsp70;    heat-shock protein of 70 kDa;    T.DnaK·DnaJ complex;    DnaK·DnaJ complex of T. thermophilus;    T.GrpE;    GrpE of T. thermophilus;   

DOI  :  10.1016/S0014-5793(97)00847-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

K⁺ is an indispensable cofactor for ATPase activity of eukaryotic cytosolic Hsp70 chaperone systems which lack a GrpE homolog. In the case of the bacterial Hsp70 (DnaK) system, GrpE, a nucleotide exchange factor, stimulates ATPase activity but little is known about the effect of K⁺. Here, we have cloned a grpE gene from a thermophile, Thermus thermophilus, and purified a homodimeric GrpE protein. Using proteins of this bacterium, we found that the GrpE stimulation of ATPase activity of DnaK·DnaJ complex was absolutely dependent on the presence of K⁺.

【 授权许可】

Unknown