1NGF: Structural Basis Of The 70-Kilodalton Heat Shock Cognate Protein Atp Hydrolytic Activity, Ii. Structure Of The Active Site With Adp Or Atp Bound To Wild Type And Mutant Atpase Fragment

Citation:
Abstract
The ATPase fragment of the bovine 70-kDa heat shock cognate protein is an attractive construct in which to study its mechanism of ATP hydrolysis. The three-dimensional structure suggests several residues that might participate in the ATPase reaction. Four acidic residues (Asp-10, Glu-175, Asp-199, and Asp-206) have been individually mutated to both the cognate amine (asparagine/glutamine) and to serine, and the effects of the mutations on the kinetics of the ATPase activity (Wilbanks, S. M., DeLuca-Flaherty, C., and McKay, D. B. (1994) J. Biol. Chem. 269, 12893-12898) and the structure of the mutant ATPase fragments have been determined, typically to approximately 2.4 A resolution. Additionally, the structures of the wild type protein complexed with MgADP and Pi, MgAMPPNP (5'-adenylyl-beta, gamma-imidodiphosphate) and CaAMPPNP have been refined to 2.1, 2.4, and 2.4 A, respectively. Combined, these structures provide models for the prehydrolysis, MgATP-bound state and the post-hydrolysis, MgADP-bound state of the ATPase fragment. These models suggest a pathway for the hydrolytic reaction in which 1) the gamma phosphate of bound ATP reorients to form a beta, gamma-bidentate phosphate complex with the Mg2+ ion, allowing 2) in-line nucleophilic attack on the gamma phosphate by a H2O molecule or OH- ion, with 3) subsequent release of inorganic phosphate.
PDB ID: 1NGFDownload
MMDB ID: 56953
PDB Deposition Date: 1994/5/17
Updated in MMDB: 2012/12
Experimental Method:
x-ray diffraction
Resolution: 2.17  Å
Source Organism:
Similar Structures:
Biological Unit for 1NGF: monomeric; determined by author
Molecular Components in 1NGF
Label Count Molecule
Protein (1 molecule)
1
Heat-shock Cognate 70 KD Protein(Gene symbol: HSPA8)
Molecule annotation
Chemical (1 molecule)
1
1
* Click molecule labels to explore molecular sequence information.

Citing MMDB
.