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Updated: Jul 31, 2026

Measuring the Kinetics of mRNA Transcription in Single Living Cells
Published on: August 25, 2011
A freeze-frame view of eukaryotic transcription during elongation and capping of nascent mRNA
Abstract:
Ribonuclease footprinting of nascent messenger RNA within ternary complexes of vaccinia RNA polymerase revealed an RNA binding site that encompasses an 18-nucleotide RNA segment. The dimensions of the binding site did not change as the polymerase moved along the template. Capping of the 5' end of the RNA was cotranscriptional and was confined to nascent chains 31 nucleotides or greater in length. Purified capping enzyme formed a binary complex with RNA polymerase in solution in the absence of nucleic acid. These findings suggest a mechanism for cotranscriptional establishment of messenger RNA identity in eukaryotes.
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