The 'glutamate switch' provides a link between ATPase activity and ligand binding in AAA+ proteins
Xiaodong Zhang1, Dale B Wigley
1Division of Molecular Biosciences, Centre for Structural Biology, Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW72AZ, UK. Xiaodong.Zhang@imperial.ac.uk
Abstract:
AAA+ proteins carry out diverse functions in cells. In most cases, their ATPase activity is tightly regulated by protein partners and target ligands, but the mechanism for this control has remained unclear. We have identified a conserved link between the ligand binding and ATPase sites in AAA+ proteins. This link, which we call the 'glutamate switch', regulates ATPase activity directly in response to the binding of target ligands by controlling the orientation of the conserved glutamate residue in the DExx motif, switching it between active and inactive conformations. The reasons for this level of control of the ATPase activity are discussed in the context of the biological processes catalyzed by AAA+ proteins.
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