RNA polymerase II complexes in the very early phase of transcription are not susceptible to TFIIS-induced exonucleolytic cleavage.
TFIIS is a transcription elongation factor for RNA polymerase II (pol II), which can suppress ribonucleotide misincorporation. We reconstituted transcription complexes in a highly purified pol II system on adenovirus Major-Late promoter constructs. We noted that these complexes have a high propensity for read-through upon GTP omission. Read-through occurred during the early stages at all registers analyzed. Addition of TFIIS reversed read-through of productive elongation complexes, which indicated that it was due to misincorporation. However, before register 13 transcription complexes were insensitive to TFIIS. These findings are discussed with respect to the structural models for pol II and we propose that TFIIS action is linked to the RNA:DNA hybrid.
Sijbrandi
Robert
R
Laboratory for Physiological Chemistry, UMCU, Stratenum, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands.
Fiedler
Ulrike
U
Timmers
H Th Marc
HT
D000256:Adenoviridae / Q000235:genetics; D001483:Base Sequence; D004247:DNA / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D046911:Macromolecular Substances; D009154:Mutation; D009692:Nucleic Acid Heteroduplexes / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D012313:RNA / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D012319:RNA Polymerase II / Q000737:chemistry* / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D013698:Templates, Genetic; D014157:Transcription Factors / Q000378:metabolism*; D035165:Transcription Factors, General; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors
D046911:Macromolecular Substances; D009692:Nucleic Acid Heteroduplexes; D014157:Transcription Factors; D035165:Transcription Factors, General; D035602:Transcriptional Elongation Factors; C018648:transcription factor S-II; D012313:RNA; D004247:DNA; D012319:RNA Polymerase II