PDBsum entry: 1izr

Hydrolase

PDB id: 1izr

Contents

Protein chain

124 a.a. *

Waters ×193

* Residue conservation analysis

PDB id:

1izr

Name:

Hydrolase

Title:

F46a mutant of bovine pancreatic ribonuclease a

Structure:

Ribonuclease a. Chain: a. Synonym: ribonuclease pancreatic. Engineered: yes. Mutation: yes

Source:

Bos taurus. Cattle. Organism_taxid: 9913. Tissue: pancreas. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

1.50Å R-factor: 0.198 R-free: 0.226

Authors:

T.Kadonosono,E.Chatani,R.Hayashi,H.Moriyama,T.Ueki

Key ref:

T.Kadonosono et al. (2003). Minimization of cavity size ensures protein stability and folding: structures of Phe46-replaced bovine pancreatic RNase A. Biochemistry, 42, 10651-10658. PubMed id: 12962489 DOI: 10.1021/bi034499w

Date:

11-Oct-02 Release date: 25-Nov-03

Protein chain

P61823  (RNAS1_BOVIN) -  Ribonuclease pancreatic

Seq: 150 a.a.

Struc: 124 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: E.C.3.1.27.5 - Pancreatic ribonuclease.
• Reaction: Endonucleolytic cleavage to nucleoside 3'-phosphates and 3'-phosphooligonucleotides ending in C-P or U-P with 2',3'-cyclic phosphate intermediates.

 Gene Ontology (GO) functional annotation 

• Cellular component: extracellular region (1 term)
• Biochemical function: nucleic acid binding (6 terms)

DOI no: 10.1021/bi034499w

Biochemistry 42:10651-10658 (2003)

PubMed id: 12962489

Minimization of cavity size ensures protein stability and folding: structures of Phe46-replaced bovine pancreatic RNase A.

T.Kadonosono, E.Chatani, R.Hayashi, H.Moriyama, T.Ueki.

ABSTRACT

The Phe46 residue, located in the hydrophobic core of RNase A, was replaced with other hydrophobic residues, leucine, valine, or alanine, and their X-ray crystallographic structures were determined up to 1.50-1.80 A resolution in an attempt to examine the relationship between structural changes and conformational stability or folding kinetics. The backbone structure of F46L, F46V, and F46A was indistinguishable from that of the wild-type enzyme, retaining the correct active site structure. However, one water molecule was included in the hydrophobic core of F46A, forming two hydrogen bonds with the backbone peptide chain. The side chain of Met29 in F46V and F46A adopted two different conformations in an equal occupancy. A trapped water molecule and two conformations of Met29 represent changes that minimize the cavity volume. Nevertheless, the replacement of Phe46 with the above residues resulted in a marked decrease in both thermal stability and folding reaction. Thus, Phe46 ensures the thermal stability and the rapid and correct folding of RNase A by the role it plays in forming a highly packed, hydrophobic core.