A possible mechanism responsible for the correction of transcription errors

• Published in: Nucleic acids research Vol. 6; no. 4; pp. 1535 - 1546
• Main Authors: Volloch, V.Z., Rits, S., Tumerman, L.
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.04.1979
• Subjects: DNA-Directed RNA Polymerases - metabolism; Escherichia coli; Escherichia coli - enzymology; Kinetics; Phosphoric Monoester Hydrolases - metabolism; Ribonucleotides; Substrate Specificity; Transcription, Genetic
• ISSN: 0305-1048; 1362-4962
• DOI: 10.1093/nar/6.4.1535

Nucleoside triphosphate phosphohydrolase (NTPase) activity was found in a preparation of E. Coli RNA polymerase. This enzymatic activity is capaable of hydrolysing all four ribonucleoside triphosphates to the nucleoside diphosphates. However, during in vitro RNA synthesis directed by poly(dC) or poly(dT), only the non-complementary nucleoside triphosphate of the same heterocyclic class was hydrolysed. No incorporation of the non-complementary precursor into RNA could be detected in these experiments. When another RNA polymerase preparation, devoid of NTPase activity, was employed, there was no hydrolysis of any nucleoside triphosphate and significant incorporation of non-complemtary precursor into RNA was observed. These observations lead us to the conclusion that NTPase, acting in conjunction with RNA polymerase, has the function of correcting errors in transcription.