2j46

Publication Abstract from PubMed

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.

Analysis of protein hydration in ultrahigh-resolution structures of the SRP GTPase Ffh.,Ramirez UD, Freymann DM Acta Crystallogr D Biol Crystallogr. 2006 Dec;62(Pt 12):1520-34. Epub 2006, Nov 23. PMID:17139088^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.