Structural highlights
Function[CLPX_ECOLI] ATP-dependent specificity component of the Clp protease. It directs the protease to specific substrates. It may bind to the lambda O substrate protein and present it to the ClpP protease in a form that can be recognized and readily hydrolyzed by ClpP. Can perform chaperone functions in the absence of ClpP.[HAMAP-Rule:MF_00175] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedClpX is a AAA+ machine that uses the energy of ATP binding and hydrolysis to unfold native proteins and translocate unfolded polypeptides into the ClpP peptidase. The crystal structures presented here reveal striking asymmetry in ring hexamers of nucleotide-free and nucleotide-bound ClpX. Asymmetry arises from large changes in rotation between the large and small AAA+ domains of individual subunits. These differences prevent nucleotide binding to two subunits, generate a staggered arrangement of ClpX subunits and pore loops around the hexameric ring, and provide a mechanism for coupling conformational changes caused by ATP binding or hydrolysis in one subunit to flexing motions of the entire ring. Our structures explain numerous solution studies of ClpX function, predict mechanisms for pore elasticity during translocation of irregular polypeptides, and suggest how repetitive conformational changes might be coupled to mechanical work during the ATPase cycle of ClpX and related molecular machines. Structures of asymmetric ClpX hexamers reveal nucleotide-dependent motions in a AAA+ protein-unfolding machine.,Glynn SE, Martin A, Nager AR, Baker TA, Sauer RT Cell. 2009 Nov 13;139(4):744-56. PMID:19914167[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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