Phosphorolytic error correction during transcription.

R T Libby; J A Gallant

doi:10.1111/j.1365-2958.1994.tb01001.x

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PubMed · 7520115

Phosphorolytic error correction during transcription.

R T Libby·J A Gallant

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Abstract

Escherichia coli DNA-directed RNA polymerase is shown to contain a novel phosphorolytic error correction activity which removes erroneous nucleotides, as rNDPs, from the 3'-end of the growing transcript. The activity we describe is biochemically similar to polynucleotide phosphorylase (PNP), yet in contrast to PNP is activated by Mn2+. We demonstrate that the activity, which is mediated by Pi, is dependent on the presence of an incorrectly incorporated nucleotide at the leading 3'-end of the transcript. The correction activity we describe exhibits a 4 x 10(4)-fold preference for the excision of incorrect nucleotides from the transcript. These findings suggest the possibility that RNA phosphorolysis may play a critical role in the process of transcriptional proofreading.

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Bacterial Proteins Enzyme Activation Escherichia coli Manganese Phosphates Polyribonucleotide Nucleotidyltransferase RNA Polymerase I RNA, Bacterial Ribonuclease H Ribonucleotides Transcription, Genetic Journal Article Research Support, U.S. Gov't, P.H.S.

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R T Libby, J A Gallant. 1994. Phosphorolytic error correction during transcription.. https://doi.org/10.1111/j.1365-2958.1994.tb01001.x

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