2SAR

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

Summary for 2SAR

• Entry DOI: 10.2210/pdb2sar/pdb
• Descriptor: RIBONUCLEASE SA, SULFATE ION, GUANOSINE-3'-MONOPHOSPHATE, ... (4 entities in total)
• Functional Keywords: hydrolase (endoribonuclease)
• Biological source: Streptomyces aureofaciens
• Cellular location: Secreted: P05798
• Total number of polymer chains: 2
• Total formula weight: 21724.41

Authors

Sevcik, J.,Dodson, E.J.,Dodson, G.G. (deposition date: 1990-12-13, release date: 1992-04-15, Last modification date: 2024-10-09)

Primary citation

Sevcik, J.,Dodson, E.J.,Dodson, G.G.
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

PubMed Abstract: 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.

PubMed: 1654932
DOI: 10.1107/S0108768190009569

Experimental method

X-RAY DIFFRACTION (1.8 Å)