4I9K

Crystal structure of symmetric W-W-W ClpX Hexamer

Summary for 4I9K

• Entry DOI: 10.2210/pdb4i9k/pdb
• Related: 3HTE 3HWS 4I34 4I4L 4I5O 4I63 4I81
• Descriptor: ATP-dependent Clp protease ATP-binding subunit ClpX, SULFATE ION (2 entities in total)
• Functional Keywords: atpase, symmetric, hexamer, motor protein
• Biological source: Escherichia coli
• Total number of polymer chains: 2
• Total formula weight: 79255.84

Authors

Glynn, S.E.,Nager, A.R.,Stinson, B.S.,Schmitz, K.R.,Baker, T.A.,Sauer, R.T. (deposition date: 2012-12-05, release date: 2013-05-15, Last modification date: 2023-09-20)

Primary citation

Stinson, B.M.,Nager, A.R.,Glynn, S.E.,Schmitz, K.R.,Baker, T.A.,Sauer, R.T.
Nucleotide Binding and Conformational Switching in the Hexameric Ring of a AAA+ Machine.
Cell(Cambridge,Mass.), 153:628-639, 2013

PubMed Abstract: ClpX, a AAA+ ring homohexamer, uses the energy of ATP binding and hydrolysis to power conformational changes that unfold and translocate target proteins into the ClpP peptidase for degradation. In multiple crystal structures, some ClpX subunits adopt nucleotide-loadable conformations, others adopt unloadable conformations, and each conformational class exhibits substantial variability. Using mutagenesis of individual subunits in covalently tethered hexamers together with fluorescence methods to assay the conformations and nucleotide-binding properties of these subunits, we demonstrate that dynamic interconversion between loadable and unloadable conformations is required to couple ATP hydrolysis by ClpX to mechanical work. ATP binding to different classes of subunits initially drives staged allosteric changes, which set the conformation of the ring to allow hydrolysis and linked mechanical steps. Subunit switching between loadable and unloadable conformations subsequently isomerizes or resets the configuration of the nucleotide-loaded ring and is required for mechanical function.

PubMed: 23622246
DOI: 10.1016/j.cell.2013.03.029

Experimental method

X-RAY DIFFRACTION (5.0003 Å)