Misplaced Pages

#905094

6-555: This bacterial enzyme contains subunits of two types, ClpP , with peptidase activity, and the protein ClpA, with AAA+ ATPase activity. ClpP and ClpA are not evolutionarily related. A fully assembled Clp protease complex has a barrel-shaped structure in which two stacked heptameric ring of proteolytic subunits ( ClpP or ClpQ) are either sandwiched between two rings or single-caped by one ring of hexameric ATPase-active chaperon subunits (ClpA, ClpC, ClpE, ClpX , ClpY, or others). ClpXP

12-632: Is homologous to the ATPase-active chaperon subunits found in the Clp complex; as such the entire group is often referred to as the HSP100/Clp family. The family is usually broken into two parts, one being the ClpA/B family with two ATPase domains, and the other being ClpX and friends with only one such domain. ClpA through E is put into the first group along with Hsp78/104, and ClpX and HSIU is put into

18-630: Is presented in almost all bacteria while ClpA is found in the Gram-negative bacteria, ClpC in Gram-Positive bacteria and cyanobacteria. ClpAP, ClpXP and ClpYQ coexist in E. coli while only ClpXP complex in present in humans as mitochondrial enzymes. ClpYQ is another name for the HslVU complex, a heat shock protein complex thought to resemble the hypothetical ancestor of the proteasome . The Hsp100 family of eukaryotic heat shock proteins

24-624: The ClpA/B family termed ClpV is used in the bacterial T6SS . Clp protease family In molecular biology, the CLP protease family is a family of serine peptidases belong to the MEROPS peptidase family S14 (ClpP endopeptidase family, clan SK). ClpP is an ATP -dependent protease that cleaves a number of proteins , such as casein and albumin . It exists as a heterodimer of ATP-binding regulatory A and catalytic P subunits, both of which are required for effective levels of protease activity in

30-609: The presence of ATP, although the P subunit alone does possess some catalytic activity. Proteases highly similar to ClpP have been found to be encoded in the genome of bacteria , in the mitochondria of metazoa , some viruses and in the chloroplast of plants . A number of the proteins in this family are classified as non-peptidase homologues as they have been found experimentally to be without peptidase activity, or lack amino acid residues that are believed to be essential for catalytic activity. Mutations in mitochondrial CLPP are associated with Perrault syndrome and cause

36-400: The second group. Many of the proteins are not associated with a protease and have functions other than proteolysis. ClpB (human CLPB "Hsp78", yeast Hsp104 ) break up insoluble protein aggregates in conjunction with DnaK/ Hsp70 . They are thought to function by threading client proteins through a small 20 Å (2 nm ) pore, thereby giving each client protein a second chance to fold. A member of

#905094