Direct modulation of RNA polymerase core functions by basal transcription factors.
Archaeal RNA polymerases (RNAPs) are recruited to promoters through the joint action of three basal transcription factors: TATA-binding protein, TFB (archaeal homolog of TFIIB), and TFE (archaeal homolog of TFIIE). Our results demonstrate several new insights into the mechanisms of TFB and TFE during the transcription cycle. (i) The N-terminal Zn ribbon of TFB displays a surprising degree of redundancy for the recruitment of RNAP during transcription initiation in the archaeal system. (ii) The B-finger domain of TFB participates in transcription initiation events by stimulating abortive and productive transcription in a recruitment-independent function. TFB thus combines physical recruitment of the RNAP with an active role in influencing the catalytic properties of RNAP during transcription initiation. (iii) TFB mutations are complemented by TFE, thereby demonstrating that both factors act synergistically during transcription initiation. (iv) An additional function of TFE is to dynamically alter the nucleic acid-binding properties of RNAP by stabilizing the initiation complex and destabilizing elongation complexes.
Werner
Finn
F
Department of Biological Sciences, Division of Cell and Molecular Biology, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom.
Weinzierl
Robert O J
RO
D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D019641:DNA, Archaeal / Q000378:metabolism; D017015:Methanococcales / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D012319:RNA Polymerase II / Q000378:metabolism*; D017384:Sequence Deletion; D035581:Transcription Factor TFIIB / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D015032:Zinc / Q000378:metabolism
D019843:Archaeal Proteins; D019641:DNA, Archaeal; D035581:Transcription Factor TFIIB; D014157:Transcription Factors; C106466:transcription factor B, Archaea; D012319:RNA Polymerase II; D015032:Zinc