Recognition, targeting, and hydrolysis of the lambda O replication proteinby the ClpP ClpX protease

Citation
M. Gonciarz-swiatek et al., Recognition, targeting, and hydrolysis of the lambda O replication proteinby the ClpP ClpX protease, J BIOL CHEM, 274(20), 1999, pp. 13999-14005
Citations number
53
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
JOURNAL OF BIOLOGICAL CHEMISTRY
ISSN journal
0021-9258 → ACNP
Volume
274
Issue
20
Year of publication
1999
Pages
13999 - 14005
Database
ISI
SICI code
0021-9258(19990514)274:20<13999:RTAHOT>2.0.ZU;2-N
Abstract
It has previously been established that sequences at the C termini of polyp eptide substrates are critical for efficient hydrolysis by the ClpP/ClpX AT P-dependent protease, We report for the bacteriophage lambda O replication protein, however, that N-terminal sequences play the most critical role in facilitating proteolysis by ClpP/ClpX The N-terminal portion of lambda O is degraded at a rate comparable with that of wild type O protein, whereas th e C-terminal domain of O is hydrolyzed at least 10-fold more slowly. Consis tent with these results, deletion of the first 18 amino acids of lambda O b locks degradation of the N-terminal domain, whereas proteolysis of the O C- terminal domain is only slightly diminished as a result of deletion of the C-terminal 15 amino acids. We demonstrate that ClpX retains its capacity to bind to the N-terminal domain following removal of the first 18 amino acid s of O, However, ClpX cannot efficiently promote the ATP-dependent binding of this truncated O polypeptide to ClpP, the catalytic subunit of the ClpP/ ClpX protease, Based on our results with lambda O protein, we suggest that two distinct structural elements may be required in substrate polypeptides to enable efficient hydrolysis by the ClpP/ClpX protease: (i) a ClpX-bindin g site, which may be located remotely from substrate termini, and (ii) a pr oper N- or C-terminal sequence, whose exposure on the substrate surface may be induced by the binding of ClpX.