2sar
From Proteopedia
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DETERMINATION AND RESTRAINED LEAST-SQUARES REFINEMENT OF THE CRYSTAL STRUCTURES OF RIBONUCLEASE SA AND ITS COMPLEX WITH 3'-GUANYLIC ACID AT 1.8 ANGSTROMS RESOLUTION
Overview
The crystal structures of ribonuclease from Streptomyces aureofaciens (RNase Sa) and its complex with 3'-guanylic acid (guanosine 3'-monophosphate, 3'-GMP) have been determined by the method of isomorphous replacement. The atomic parameters have been refined by restrained least-squares minimization using data in the resolution range 10.0-1.8 A. All protein atoms and more than 230 water atoms in the two crystal structures have been refined to crystallographic R factors of 0.172 and 0.175 respectively. The estimated r.m.s. error in the atomic positions ranges from 0.2 A for well-defined atoms to about 0.5 A for more poorly defined atoms. There are two enzyme molecules in the asymmetric unit, built independently, and referred to as molecules A and B. The value of the average B factor for protein atoms in both structures is about 19 A2 and for water molecules about 35 A2. Electron density for the substrate analogue 3'-GMP was found only at the active site of molecule A. The density was very clear and the positions of all 3'-GMP atoms were refined with precision comparable to that of the protein.
About this Structure
2SAR is a Single protein structure of sequence from Streptomyces aureofaciens with and as ligands. Active as Ribonuclease T(1), with EC number 3.1.27.3 Full crystallographic information is available from OCA.
Reference
Determination and restrained least-squares refinement of the structures of ribonuclease Sa and its complex with 3'-guanylic acid at 1.8 A resolution., Sevcik J, Dodson EJ, Dodson GG, Acta Crystallogr B. 1991 Apr 1;47 ( Pt 2):240-53. PMID:1654932
Page seeded by OCA on Thu Feb 21 18:48:57 2008
