Crystal Structure of Heat Shock Locus V (HslV) from Escherichia coli
Abstract
Heat shock locus V (HslV; also called ClpQ) is the proteolytic core of the ATP-dependent protease HslVU in Escherichia coli. It has sequence similarity with the β-type subunits of the eukaryotic and archaebacterial proteasomes. Unlike these particles, which display 72-point symmetry, it is a dimer of hexamers with 62-point symmetry. The crystal structure of HslV at 3.8-å resolution, determined by isomorphous replacement and symmetry averaging, shows that in spite of the different symmetry of the particle, the fold and the contacts between subunits are conserved. A tripeptide aldehyde inhibitor, acetyl-Leu-Leu-norleucinal, binds to the N-terminal threonine residue of HslV, probably as a hemiacetal, relating HslV also functionally to the proteasomes of archaea and eukaryotes.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- June 1997
- DOI:
- 10.1073/pnas.94.12.6070
- Bibcode:
- 1997PNAS...94.6070B