2J46 : Water structure of T. Aquaticus Ffh NG Domain At 1.1A Resolution

  • Ursula D. Ramirez (Contributor)
  • Douglas M. Freymann (Contributor)



Experimental Technique/Method:X-RAY DIFFRACTION
Release Date:2006-11-30
Deposition Date:2006-08-24
Revision Date:2011-05-08#2011-07-13
Molecular Weight:65749.4
Macromolecule Type:Protein
Residue Count:594
Atom Site Count:5337

Two new structures of the SRP GTPase Ffh have been determined at 1.1 A resolution and provide the basis for comparative examination of the extensive water structure of the apo conformation of these GTPases. A set of well defined water-binding positions have been identified in the active site of the two-domain ;NG' GTPase, as well as at two functionally important interfaces. The water hydrogen-bonding network accommodates alternate conformations of the protein side chains by undergoing local rearrangements and, in one case, illustrates binding of a solute molecule within the active site by displacement of water molecules without further disruption of the water-interaction network. A subset of the water positions are well defined in several lower resolution structures, including those of different nucleotide-binding states; these appear to function in maintaining the protein structure. Consistent arrangements of surface water between three different ultrahigh-resolution structures provide a framework for beginning to understand how local water structure contributes to protein-ligand and protein-protein binding in the SRP GTPases.
Date made available2006

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