Interaction specificity between the chaperone and proteolytic components of the cyanobacterial Clp protease.
The Clp protease is conserved among eubacteria and most eukaryotes, and uses ATP to drive protein substrate unfolding and translocation into a chamber of sequestered proteolytic active sites. In plant chloroplasts and cyanobacteria, the essential constitutive Clp protease consists of the Hsp100/ClpC chaperone partnering a proteolytic core of catalytic ClpP and noncatalytic ClpR subunits. In the present study, we have examined putative determinants conferring the highly specific association between ClpC and the ClpP3/R core from the model cyanobacterium Synechococcus elongatus. Two conserved sequences in the N-terminus of ClpR (tyrosine and proline motifs) and one in the N-terminus of ClpP3 (MPIG motif) were identified as being crucial for the ClpC-ClpP3/R association. These N-terminal domains also influence the stability of the ClpP3/R core complex itself. A unique C-terminal sequence was also found in plant and cyanobacterial ClpC orthologues just downstream of the P-loop region previously shown in Escherichia coli to be important for Hsp100 association to ClpP. This R motif in Synechococcus ClpC confers specificity for the ClpP3/R core and prevents association with E. coli ClpP; its removal from ClpC reverses this core specificity.
Department of Biological and Environmental Sciences, Gothenburg University, Box 461, S-405 30 Göteborg, Sweden.
Anders
A
Tryggvesson
Frida M
FM
Ståhlberg
Axel
A
Mogk
Kornelius
K
Zeth
Adrian K
AK
Clarke
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002364:Caseins / Q000378:metabolism; D017124:Conserved Sequence; D049071:Endopeptidase Clp / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D056384:Group I Chaperonins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D054730:Protein Interaction Domains and Motifs; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D059748:Proteolysis; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D046940:Synechococcus / Q000201:enzymology*
D001426:Bacterial Proteins; D002364:Caseins; C087481:ClpC protein, Bacteria; D006360:Heat-Shock Proteins; D010446:Peptide Fragments; D021122:Protein Subunits; D011993:Recombinant Fusion Proteins; D049071:Endopeptidase Clp; D056384:Group I Chaperonins