TY - JOUR
T1 - Recognition, targeting, and hydrolysis of the λ O replication protein by the ClpP/ClpX protease
AU - Gonciarz-Swiatek, Malgorzata
AU - Wawrzynow, Alicja
AU - Um, Soo Jong
AU - Learn, Brian A.
AU - McMacken, Roger
AU - Kelley, William L.
AU - Georgopoulos, Costa
AU - Sliekers, Olaf
AU - Zylicz, Maciej
PY - 1999/5/14
Y1 - 1999/5/14
N2 - It has previously been established that sequences at the C termini of polypeptide substrates are critical for efficient hydrolysis by the ClpP/ClpX ATP-dependent protease. We report for the bacteriophage λ O replication protein, however, that N-terminal sequences play the most critical role in facilitating proteolysis by ClpP/ClpX. The N-terminal portion of λ O is degraded at a rate comparable with that of wild type O protein, whereas the C-terminal domain of O is hydrolyzed at least 10-fold more slowly. Consistent with these results, deletion of the first 18 amino acids of λ O blocks 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 acids 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 λ 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-binding site, which may be located remotely from substrate termini, and (ii) a proper N- or C-terminal sequence, whose exposure on the substrate surface may be induced by the binding of ClpX.
AB - It has previously been established that sequences at the C termini of polypeptide substrates are critical for efficient hydrolysis by the ClpP/ClpX ATP-dependent protease. We report for the bacteriophage λ O replication protein, however, that N-terminal sequences play the most critical role in facilitating proteolysis by ClpP/ClpX. The N-terminal portion of λ O is degraded at a rate comparable with that of wild type O protein, whereas the C-terminal domain of O is hydrolyzed at least 10-fold more slowly. Consistent with these results, deletion of the first 18 amino acids of λ O blocks 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 acids 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 λ 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-binding site, which may be located remotely from substrate termini, and (ii) a proper N- or C-terminal sequence, whose exposure on the substrate surface may be induced by the binding of ClpX.
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U2 - 10.1074/jbc.274.20.13999
DO - 10.1074/jbc.274.20.13999
M3 - Article
C2 - 10318812
AN - SCOPUS:0033553474
SN - 0021-9258
VL - 274
SP - 13999
EP - 14005
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 20
ER -