Mais complexidade, Darwin: A modelagem de precisão transcricional sugere duas etapas de revisão pela polimerase do RNA

terça-feira, outubro 03, 2017

Transcriptional accuracy modeling suggests two-step proofreading by RNA polymerase 

Harriet Mellenius Måns Ehrenberg

Nucleic Acids Research, gkx849,

Published: 28 September 2017 

Article history

Received: 04 August 2016 Revision Received: 10 September 2017

Accepted: 22 September 2017

Source/Fonte: Nucleic Acids Research


We suggest a novel two-step proofreading mechanism with two sequential rounds of proofreading selection in mRNA transcription. It is based on the previous experimental observations that the proofreading RNA polymerase cleaves off transcript fragments of at least 2 nt and that transcript elongation after a nucleotide misincorporation is anomalously slow. Taking these results into account, we extend the description of the accuracy of template guided nucleotide selection beyond previous models of RNA polymerase-dependent DNA transcription. The model derives the accuracy of initial and proofreading base selection from experimentally estimated nearest-neighbor parameters. It is also used to estimate the small accuracy enhancement of polymerase revisiting of previous positions following transcript cleavage.


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