Second transmembrane segment of FtsH plays a role in its proteolytic activity and homo‐oligomerization

FEBS Letters

Kitagawa, Masanari⁴  Wakagi, Takayoshi²  Makino, Shin-ichi²  Abe, Kunitake²  Matsuzawa, Hiroshi²  Fujii, Tomoyuki³  Makinoa, Tomohiro²  Tatsuta, Takashi⁴  Mori, Hirotada⁴  Ogura, Teru¹  Hashimoto, Junko⁴  Fushinobu, Shinya² 

[1] Institute of Molecular Embryology and Genetics, Kumamoto University School of Medicine, Kumamoto 862-0976, Japan;Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan;Department of Applied Biological Chemistry, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan;Research and Education Center for Genetic Information, Nara Institute of Science and Technology, Ikoma 630-0101, Japan

关键词: ATP-dependent protease;    FtsH/HflB;    Homo-oligomerization;    Water-soluble MBP-FtsH fusion;    AAA protein family;   

DOI  :  10.1016/S0014-5793(99)01411-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The FtsH (HflB) protein of Escherichia coli is a membrane-bound ATP-dependent zinc protease. The role(s) of the N-terminal membrane-anchoring region of FtsH were studied by fusion with a maltose-binding protein (MBP) at five different N-termini of FtsH. The MBP-FtsH fusions were expressed in the cytoplasm of E. coli, and were purified as soluble proteins. The four longer constructs, which have a second transmembrane segment and the C-terminal cytoplasmic region in common, retained ATP-dependent protease activity toward heat-shock transcription factor σ³², and were found to be homo-oligomers. In contrast, the shortest construct which has the C-terminal cytoplasmic region but not the second transmembrane segment showed neither protease activity nor oligomerization. Therefore, the second transmembrane segment, which neighbors the C-terminal cytoplasmic region of the FtsH, participates in not only its membrane-anchoring, but also its protease activity and homo-oligomerization.

【 授权许可】

Unknown