3pxg | pdb_00003pxg
Structure of MecA121 and ClpC1-485 complex
Structural highlights
Function[MECA1_BACSU] Enables the recognition and targeting of unfolded and aggregated proteins to the ClpC protease or to other proteins involved in proteolysis. Acts negatively in the development of competence by binding ComK and recruiting it to the ClpCP protease. When overexpressed, inhibits sporulation. Also involved in Spx degradation by ClpC.[1] [CLPC_BACSU] Competence gene repressor; required for cell growth at high temperature. Negative regulator of comK expression. May interact with MecA to negatively regulate comK. Publication Abstract from PubMedRegulated proteolysis by ATP-dependent proteases is universal in all living cells. Bacterial ClpC, a member of the Clp/Hsp100 family of AAA+ proteins (ATPases associated with diverse cellular activities) with two nucleotide-binding domains (D1 and D2), requires the adaptor protein MecA for activation and substrate targeting. The activated, hexameric MecA-ClpC molecular machine harnesses the energy of ATP binding and hydrolysis to unfold specific substrate proteins and translocate the unfolded polypeptide to the ClpP protease for degradation. Here we report three related crystal structures: a heterodimer between MecA and the amino domain of ClpC, a heterododecamer between MecA and D2-deleted ClpC, and a hexameric complex between MecA and full-length ClpC. In conjunction with biochemical analyses, these structures reveal the organizational principles behind the hexameric MecA-ClpC complex, explain the molecular mechanisms for MecA-mediated ClpC activation and provide mechanistic insights into the function of the MecA-ClpC molecular machine. These findings have implications for related Clp/Hsp100 molecular machines. Structure and mechanism of the hexameric MecA-ClpC molecular machine.,Wang F, Mei Z, Qi Y, Yan C, Hu Q, Wang J, Shi Y Nature. 2011 Mar 2. PMID:21368759[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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