2SAR image
Deposition Date 1990-12-13
Release Date 1992-04-15
Last Version Date 2024-10-09
Entry Detail
PDB ID:
2SAR
Title:
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
Biological Source:
Source Organism:
Method Details:
Experimental Method:
Resolution:
1.80 Å
R-Value Observed:
0.17
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:RIBONUCLEASE SA
Gene (Uniprot):rnaSA
Chain IDs:A, B
Chain Length:96
Number of Molecules:2
Biological Source:Streptomyces aureofaciens
Primary Citation
Determination and restrained least-squares refinement of the structures of ribonuclease Sa and its complex with 3'-guanylic acid at 1.8 A resolution.
Acta Crystallogr.,Sect.B 47 240 253 (1991)
PMID: 1654932 DOI: 10.1107/S0108768190009569

Abstact

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.

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Primary Citation of related structures