Glu 46 of ribonuclease T1 is an essential residue for the recognition of guanine base

S Nishikawa; T Kimura; H Morioka; S Uesugi; T Hakoshima; K Tomita; E Ohtsuka; M Ikehara

doi:10.1016/0006-291x(88)90487-1

Glu 46 of ribonuclease T1 is an essential residue for the recognition of guanine base

Biochem Biophys Res Commun. 1988 Jan 15;150(1):68-74. doi: 10.1016/0006-291x(88)90487-1.

Authors

S Nishikawa¹, T Kimura, H Morioka, S Uesugi, T Hakoshima, K Tomita, E Ohtsuka, M Ikehara

Affiliation

¹ Faculty of Pharmaceutical Sciences, Osaka University, Japan.

PMID: 3122758
DOI: 10.1016/0006-291x(88)90487-1

Abstract

The Glu 46 of ribonuclease T1, which is assumed to interact with Nl of the guanine residue in RNA by a hydrogen bond from the result of X-ray analysis, was changed to alanine by site-directed mutagenesis and its function examined. The nucleolytic activity of the Ala 46 mutant enzyme against pGpC decreased to 0.4% of that of the wild-type enzyme, on the other hand its activity against pApC increased. This result suggests that the Glu 46 is essential for the recognition of the guanine base but that it also interferes with the recognition of the adenine base.

Publication types

Comparative Study
Research Support, Non-U.S. Gov't

MeSH terms

Alanine
Chromatography, High Pressure Liquid
Circular Dichroism
Electrophoresis, Polyacrylamide Gel
Endoribonucleases / metabolism*
Glutamine*
Guanine / metabolism*
Hydrogen Bonding
Hydrogen-Ion Concentration
Mutation
Oligonucleotides / metabolism
Protein Conformation
Recombinant Fusion Proteins / genetics
Recombinant Fusion Proteins / metabolism
Ribonuclease T1 / genetics
Ribonuclease T1 / metabolism*
Structure-Activity Relationship
Substrate Specificity

Substances

Oligonucleotides
Recombinant Fusion Proteins
Glutamine
Guanine
Endoribonucleases
Ribonuclease T1
Alanine