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

• Published in: FEBS letters Vol. 306; no. 2; pp. 129 - 132
• Main Authors: Rechinsky, V.O., Kostyuk, D.A., Tunitskaya, V.L., Kochetkov, S.N.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 20-07-1992; Elsevier
• Subjects: Amino Acid Sequence; Analytical, structural and metabolic biochemistry; bacteriophage T7 DNA-dependent RNA polymerase; Binding, Competitive; Biological and medical sciences; DNA-Directed RNA Polymerases - genetics; DNA-Directed RNA Polymerases - metabolism; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Kinetics; Molecular Sequence Data; Mutant form of enzyme; mutant T7RNAP containing Tyr-639→Asp substitution; Mutation; NTP binding; synthetic promoter for T7RNAP; T-Phages - enzymology; T7 RNA polymerase; T7RNAP; Transferases; Tyrosine - physiology; Viral Proteins; Y639D; T7 RNA polymerase; Mutant form of enzyme; Pr; T7RNAP; NTP binding; Y639D; Virus; Structure activity relation; Enzyme; Podoviridae; Nucleotide; Molecular interaction; Phage T7; Mutation; RNA polymerase; Phage
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(92)80983-N

Substitution or 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.