1SSC

THE 1.6 ANGSTROMS STRUCTURE OF A SEMISYNTHETIC RIBONUCLEASE CRYSTALLIZED FROM AQUEOUS ETHANOL. COMPARISON WITH CRYSTALS FROM SALT SOLUTIONS AND WITH RNASE A FROM AQUEOUS ALCOHOL SOLUTIONS

Summary for 1SSC

• Entry DOI: 10.2210/pdb1ssc/pdb
• Descriptor: RIBONUCLEASE A, PHOSPHATE ION, ... (4 entities in total)
• Functional Keywords: endonuclease
• Biological source: Bos taurus (cattle); More
• Cellular location: Secreted: P61823 P61823
• Total number of polymer chains: 2
• Total formula weight: 13707.21

Authors

De Mel, V.S.J.,Doscher, M.S.,Martin, P.D.,Rodier, F.,Edwards, B.F.P. (deposition date: 1994-10-05, release date: 1995-01-26, Last modification date: 2024-11-06)

Primary citation

de Mel, S.J.,Doscher, M.S.,Martin, P.D.,Rodier, F.,Edwards, B.F.
1.6 A structure of semisynthetic ribonuclease crystallized from aqueous ethanol. Comparison with crystals from salt solutions and with ribonuclease A from aqueous alcohol solutions.
Acta Crystallogr.,Sect.D, 51:1003-1012, 1995

PubMed Abstract: The non-covalent combination of residues 1-118 of RNase A with a synthetic 14-residue peptide containing residues 111-124 of the molecule forms a highly active semisynthetic enzyme, RNase 1-118:111-124. With this enzyme, the roles played by the six C-terminal residues in generating the catalytic efficiency and substrate specificity of RNase can be studied using chemically synthesized analogs. The structure of RNase 1-118:111-124 from 43% aqueous ethanol has been determined using molecular-replacement methods and refined to a crystallographic R-factor of 0.166 for all observed reflections in the range 7.0-1.6 A (Protein Data Bank file ISSC). The structure is compared with the 2.0 A structure of RNase A from 43% aqueous 2-methyl-2-propanol and with the 1.8 A structure of the semisynthetic enzyme obtained from crystals grown in concentrated salt solution. The structure of RNase 1-118:111-124 from aqueous ethanol is virtually identical to that of RNase A from aqueous 2-methyl-2-propanol. Half of the crystallographically bound water molecules are not coincident, however. The structure is somewhat less similar to that of RNase 1-118:111-124 from salt solutions, with a major difference being the positioning of active-site residue His119.

PubMed: 15299768
DOI: 10.1107/S0907444995004574

Experimental method

X-RAY DIFFRACTION (2 Å)