Fidelity of RNA polymerase II transcription controlled by elongation factor TFIIS.
Fidelity of DNA and protein synthesis is regulated by a proofreading mechanism but function of a similar mechanism during RNA synthesis has not been demonstrated. Analysis of transcriptional fidelity and its control has been hampered by the necessity to employ complex DNA templates requiring either a promoter and initiation factors or 3'-extended templates. To circumvent this difficulty, we have created an RNA-DNA dumbbell template that can be recognized as a template-primer and extended by RNA polymerase II. By employing this system, we demonstrate that RNA polymerase II can misincorporate a nucleotide and carry out template-dependent elongation at the mispaired end. The transcripts containing misincorporated residues can be cleaved by the very slow 3'-->5' ribonuclease activity of the RNA polymerase II, but enhancement of this activity by the elongation factor TFIIS generates RNA with a high degree of fidelity. This enhanced preferential cleavage of misincorporated transcripts suggests an important role for TFIIS in maintaining transcriptional fidelity.
Jeon
C
C
Department of Biochemistry and Molecular Biology, University of Chicago, IL 60637, USA.
Agarwal
K
K
D000818:Animals; D001483:Base Sequence; D002417:Cattle; D004247:DNA; D007700:Kinetics; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012313:RNA; D012319:RNA Polymerase II / Q000378:metabolism*; D013698:Templates, Genetic; D013950:Thymus Gland / Q000201:enzymology; D014157:Transcription Factors / Q000378:metabolism*; D035165:Transcription Factors, General; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors
D009841:Oligonucleotides; D014157:Transcription Factors; D035165:Transcription Factors, General; D035602:Transcriptional Elongation Factors; C018648:transcription factor S-II; D012313:RNA; D004247:DNA; D012319:RNA Polymerase II