Non-cognizable ribonucleotide, 2'AMP, binds to a mutant ribonuclease T1 (Y45W) at a new base-binding site but not at the guanine-recognition site

FEBS Lett. 1991 Sep 23;290(1-2):216-20. doi: 10.1016/0014-5793(91)81263-8.

Abstract

Complex of a mutant ribonuclease T1 (Y45W) with a non-cognizable ribonucleotide, 2'AMP, has been determined and refined by X-ray diffraction at 1.7 A resolution. The 2'AMP molecule locates at a new base-binding site which is remote from the guanine-recognition site, where 2'GMP was found to be bound. The nucleotide adopts the anti conformation of the glycosidic bond and C3'-exo sugar pucker. There exists a single hydrogen bond between the adenine base and the enzyme, and, therefore, the site found is apparently a non-specific binding site. The results indicate that the binding of 2'AMP to the guanine-recognition site is weaker than that to the new binding site.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Monophosphate / metabolism*
  • Amino Acid Sequence
  • Aspergillus oryzae / enzymology
  • Binding Sites
  • Crystallography
  • Guanosine Monophosphate / metabolism
  • Hydrogen Bonding
  • Isomerism
  • Models, Molecular
  • Molecular Structure
  • Mutation
  • Recombinant Proteins / ultrastructure
  • Ribonuclease T1 / metabolism*
  • Ribonuclease T1 / ultrastructure
  • Structure-Activity Relationship
  • X-Ray Diffraction

Substances

  • Recombinant Proteins
  • 2'-guanylic acid
  • Adenosine Monophosphate
  • Guanosine Monophosphate
  • Ribonuclease T1