PDBsum entry 1ssc

Endonuclease

PDB id: 1ssc

Contents

Protein chains

112 a.a. *

11 a.a. *

Ligands

PO4

Waters ×95

* Residue conservation analysis

PDB id:

1ssc

Name:

Endonuclease

Title:

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

Structure:

Ribonuclease a. Chain: a. Engineered: yes. Ribonuclease a. Chain: b. Engineered: yes

Source:

Bos taurus. Cattle. Organism_taxid: 9913. Organism_taxid: 9913

Biol. unit:

Dimer (from PQS)

Resolution:

2.00Å R-factor: 0.166

Authors:

V.S.J.De Mel,M.S.Doscher,P.D.Martin,F.Rodier,B.F.P.Edwards

Key ref:

S.J.de Mel et al. (1995). 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 D Biol Crystallogr, 51, 1003-1012. PubMed id: 15299768 DOI: 10.1107/S0907444995004574

Date:

05-Oct-94 Release date: 26-Jan-95

Protein chain

P61823  (RNAS1_BOVIN) -  Ribonuclease pancreatic from Bos taurus

Seq: 150 a.a.

Struc: 112 a.a.

Protein chain

P61823  (RNAS1_BOVIN) -  Ribonuclease pancreatic from Bos taurus

Seq: 150 a.a.

Struc: 11 a.a.

Enzyme reactions

• Enzyme class: Chains A, B: E.C.4.6.1.18 - pancreatic ribonuclease.
• Reaction:
  1. an [RNA] containing cytidine + H2O = an [RNA]-3'-cytidine- 3'-phosphate + a 5'-hydroxy-ribonucleotide-3'-[RNA]
  2. an [RNA] containing uridine + H2O = an [RNA]-3'-uridine-3'-phosphate + a 5'-hydroxy-ribonucleotide-3'-[RNA]

DOI no: 10.1107/S0907444995004574

Acta Crystallogr D Biol Crystallogr 51:1003-1012 (1995)

PubMed id: 15299768

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.

S.J.de Mel, M.S.Doscher, P.D.Martin, F.Rodier, B.F.Edwards.

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.

Selected figure(s)

Figure 4.
Fig. 4. Electron density for Hisil9 in RNase 1-118:111-124 from aqueous ethanol. The 2F,,- F,. density peaks for the imidazole ring of Hisll9 and for the phosphate ion in RNase i-118:111-124 crystallized from aqueous ethanol contoured at 1.5cr. The side chain is in position A.

The above figure is reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (1995, 51, 1003-1012) copyright 1995.

Figure was selected by an automated process.