A sequence element located immediately upstream of the TATA element, and having the consensus sequence 5'-G/C-G/C-G/A-C-G-C-C-3', affects the ability of transcription factor IIB to enter transcription complexes and support transcription initiation. The sequence element is recognized directly by the transcription factor IIB. Recognition involves alpha-helices 4' and 5' of IIB, which comprise a helix-turn-helix DNA-binding motif. These observations establish that transcription initiation involves a fourth core promoter element, the IIB recognition element (BRE), in addition to the TATA element, the initiator element, and the downstream promoter element, and involves a second sequence-specific general transcription factor, IIB, in addition to transcription factor IID.
Amino Acid Sequence
,DNA-Binding Proteins
,Helix-Turn-Helix Motifs
,Humans
,Molecular Sequence Data
,Nucleic Acid Conformation
,Promoter Regions, Genetic
,RNA Polymerase II
,Transcription Factor TFIIB
,Transcription Factors
,Transcription, Genetic