3HTE

Crystal structure of nucleotide-free hexameric ClpX

Summary for 3HTE

• Entry DOI: 10.2210/pdb3hte/pdb
• Descriptor: ATP-dependent Clp protease ATP-binding subunit clpX, SULFATE ION (2 entities in total)
• Functional Keywords: clpx, aaa+ molecular machine, hexamer, asymmetric, atp-binding, chaperone, metal-binding, nucleotide-binding, stress response, zinc-finger, metal binding protein, motor protein
• Biological source: Escherichia coli
• Total number of polymer chains: 6
• Total formula weight: 237185.63

Authors

Glynn, S.E.,Martin, A.,Baker, T.A.,Sauer, R.T. (deposition date: 2009-06-11, release date: 2009-11-24, Last modification date: 2024-02-21)

Primary citation

Glynn, S.E.,Martin, A.,Nager, A.R.,Baker, T.A.,Sauer, R.T.
Structures of asymmetric ClpX hexamers reveal nucleotide-dependent motions in a AAA+ protein-unfolding machine.
Cell(Cambridge,Mass.), 139:744-756, 2009

PubMed Abstract: ClpX 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.

PubMed: 19914167
DOI: 10.1016/j.cell.2009.09.034

Experimental method

X-RAY DIFFRACTION (4.026 Å)