On the functional role of the Tyr-639 residue of bacteriophage T7 RNA polymerase

FEBS Lett. 1992 Jul 20;306(2-3):129-32. doi: 10.1016/0014-5793(92)80983-n.

Abstract

Substitution of Asp for a Tyr residue normally present at position 639 of the bacteriophage T7 RNA polymerase leads to a drastic drop in the enzymatic activity. This mutation does not affect the enzyme-promoter interaction but decreases the ability of the RNA polymerase to discriminate between GTP and ATP molecules, resulting in a decrease in the rate of the incorporation of the nucleotide into the RNA chain.

MeSH terms

  • Amino Acid Sequence
  • Binding, Competitive
  • DNA-Directed RNA Polymerases / genetics
  • DNA-Directed RNA Polymerases / metabolism*
  • Kinetics
  • Molecular Sequence Data
  • Mutation
  • T-Phages / enzymology
  • Tyrosine / physiology*
  • Viral Proteins

Substances

  • Viral Proteins
  • Tyrosine
  • bacteriophage T7 RNA polymerase
  • DNA-Directed RNA Polymerases