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From Proteopedia
ClpAP complex bound to ClpS N-terminal extension, class IIa
Structural highlights
FunctionCLPA_ECOLI ATP-dependent specificity component of the ClpAP protease. It directs the protease to specific substrates. It has unfoldase activity. The primary function of the ClpA-ClpP complex appears to be the degradation of unfolded or abnormal proteins. Publication Abstract from PubMedClpAP, a two-ring AAA+ protease, degrades N-end-rule proteins bound by the ClpS adaptor. Here we present high-resolution cryo-EM structures of Escherichia coli ClpAPS complexes, showing how ClpA pore loops interact with the ClpS N-terminal extension (NTE), which is normally intrinsically disordered. In two classes, the NTE is bound by a spiral of pore-1 and pore-2 loops in a manner similar to substrate-polypeptide binding by many AAA+ unfoldases. Kinetic studies reveal that pore-2 loops of the ClpA D1 ring catalyze the protein remodeling required for substrate delivery by ClpS. In a third class, D2 pore-1 loops are rotated, tucked away from the channel and do not bind the NTE, demonstrating asymmetry in engagement by the D1 and D2 rings. These studies show additional structures and functions for key AAA+ elements. Pore-loop tucking may be used broadly by AAA+ unfoldases, for example, during enzyme pausing/unloading. AAA+ protease-adaptor structures reveal altered conformations and ring specialization.,Kim S, Fei X, Sauer RT, Baker TA Nat Struct Mol Biol. 2022 Nov;29(11):1068-1079. doi: 10.1038/s41594-022-00850-3. , Epub 2022 Nov 3. PMID:36329286[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Escherichia coli | Large Structures | Baker TA | Fei X | Kim S | Sauer RT
