Format

Send to

Choose Destination
Nucleic Acids Res. 2013 Aug;41(14):7048-59. doi: 10.1093/nar/gkt433. Epub 2013 Jun 3.

The RNA polymerase trigger loop functions in all three phases of the transcription cycle.

Author information

1
Institut of Microbiology and Archaea Center, Universität Regensburg, 93053 Regensburg, Germany.

Abstract

The trigger loop (TL) forms a conserved element in the RNA polymerase active centre that functions in the elongation phase of transcription. Here, we show that the TL also functions in transcription initiation and termination. Using recombinant variants of RNA polymerase from Pyrococcus furiosus and a reconstituted transcription system, we demonstrate that the TL is essential for initial RNA synthesis until a complete DNA-RNA hybrid is formed. The archaeal TL is further important for transcription fidelity during nucleotide incorporation, but not for RNA cleavage during proofreading. A conserved glutamine residue in the TL binds the 2'-OH group of the nucleoside triphosphate (NTP) to discriminate NTPs from dNTPs. The TL also prevents aberrant transcription termination at non-terminator sites.

PMID:
23737452
PMCID:
PMC3737540
DOI:
10.1093/nar/gkt433
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Silverchair Information Systems Icon for PubMed Central
Loading ...
Support Center