Abstract
The degradation of ssrA-tagged substrates in prokaryotes is conducted by a subset of ATP-dependent proteases, including ClpXP complex. More than 630 sequences of ssrA have been identified from 514 species, and are conserved in a wide range of prokaryotes. SspB protein markedly stimulates the degradation of these ssrA-tagged substrates by the ClpXP proteolytic machine. The dimeric SspB protein is composed of a compact ssrA-binding domain, which has a dimerization surface and a flexible C-terminal tail with a ClpX-binding motif at its very end. Since SspB is an adaptor protein for the ClpXP complex, designed mutagenesis, fluorescence spectroscopy, biochemistry and X-ray crystallography have been used to investigate the mechanism of delivery of ssrA-tagged proteins. In this paper the structural basis of ssrA-tag recognition by ClpX and SspB, as well as SspB-tail recognition by ZBD, is described.
Original language | English |
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Pages (from-to) | 246-249 |
Number of pages | 4 |
Journal | Journal of Synchrotron Radiation |
Volume | 15 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2008 Apr 18 |
Keywords
- Adaptor
- ClpX
- ClpXP complex
- SspB
- SsrA
- Zinc-binding domain
ASJC Scopus subject areas
- Radiation
- Nuclear and High Energy Physics
- Instrumentation