Premium
Escherichia coli FtsH is a membrane‐bound, ATP‐dependent protease which degrades the heat‐shock transcription factor sigma 32.
Author(s) -
Tomoyasu T.,
Gamer J.,
Bukau B.,
Kanemori M.,
Mori H.,
Rutman A.J.,
Oppenheim A.B.,
Yura T.,
Yamanaka K.,
Niki H.
Publication year - 1995
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1995.tb07253.x
Subject(s) - biology , cell and molecular biology , gene , genetics , plant development
Escherichia coli FtsH is an essential integral membrane protein that has an AAA‐type ATPase domain at its C‐terminal cytoplasmic part, which is homologous to at least three ATPase subunits of the eukaryotic 26S proteasome. We report here that FtsH is involved in degradation of the heat‐shock transcription factor sigma 32, a key element in the regulation of the E. coli heat‐shock response. In the temperature‐sensitive ftsH1 mutant, the amount of sigma 32 at a non‐permissive temperature was higher than in the wild‐type under certain conditions due to a reduced rate of degradation. In an in vitro system with purified components, FtsH catalyzed ATP‐dependent degradation of biologically active histidine‐tagged sigma 32. FtsH has a zinc‐binding motif similar to the active site of zinc‐metalloproteases. Protease activity of FtsH for histidine‐tagged sigma 32 was stimulated by Zn2+ and strongly inhibited by the heavy metal chelating agent o‐phenanthroline. We conclude that FtsH is a novel membrane‐bound, ATP‐dependent metalloprotease with activity for sigma 32. These findings indicate a new mechanism of gene regulation in E. coli.