Download MendeleyConformational plasticity of the ClpAP AAA+ protease couples protein unfolding and proteolysis.
Lopez, K.E., Rizo, A.N., Tse, E., Lin, J., Scull, N.W., Thwin, A.C., Lucius, A.L., Shorter, J., Southworth, D.R.(2020) Nat Struct Mol Biol 27: 406-416
- PubMed: 32313240
- DOI: https://doi.org/10.1038/s41594-020-0409-5
- Primary Citation of Related Structures:
6UQE, 6UQO, 6W1Z, 6W20, 6W21, 6W22, 6W23, 6W24 - PubMed Abstract:
The ClpAP complex is a conserved bacterial protease that unfolds and degrades proteins targeted for destruction. The ClpA double-ring hexamer powers substrate unfolding and translocation into the ClpP proteolytic chamber. Here, we determined high-resolution structures of wild-type Escherichia coli ClpAP undergoing active substrate unfolding and proteolysis. A spiral of pore loop-substrate contacts spans both ClpA AAA+ domains. Protomers at the spiral seam undergo nucleotide-specific rearrangements, supporting substrate translocation. IGL loops extend flexibly to bind the planar, heptameric ClpP surface with the empty, symmetry-mismatched IGL pocket maintained at the seam. Three different structures identify a binding-pocket switch by the IGL loop of the lowest positioned protomer, involving release and re-engagement with the clockwise pocket. This switch is coupled to a ClpA rotation and a network of conformational changes across the seam, suggesting that ClpA can rotate around the ClpP apical surface during processive steps of translocation and proteolysis.
Organizational Affiliation:
Graduate Program in Biophysics, University of California, San Francisco, San Francisco, CA, USA.
