Gene transcriptions/Elements/Downstream TFIIB recognitions



The downstream B recognition element designated as the BREd, or dBRE, is an additional core promoter element that occurs downstream of the TATA box and is recognized by general transcription factor II B.

Consensus sequences
A consensus sequence is 5'-A/G-T-A/G/T-G/T-G/T-G/T-G/T-3' or in the transcription direction on the template strand 3'-A/G-T-A/G/T-G/T-G/T-G/T-G/T-5'.

Eukaryote genes
Of 140 promoters from the eukaryotic promoter database, "[S]ix percent ... [contain] at least six out of seven bases of the consensus sequence, 18% contain at least five of seven bases and 37% contain at least four of seven".

Human genes
GeneID: 9555 H2A histone family, member Y (H2AFY) "contains a poor TATA element, but both a consensus Inr and DPE in addition to a six/seven match BREd."

General transcription factor II Bs
A TFIIB recognition element (BRE) functions to determine the orientation of the TFIIB-TBP-TATA complex that projects the zinc ribbon of TFIIB toward the TSS.

General transcription factor II B can recognize two distinct sequence elements that flank the TATA box. "The selected sequences contain a strong representation of [ guanine (G) and thymine (T)] bases and a striking preference against [ adenine (A)] (especially between bases -17 and -20)."

"[T]here are ... some weakly conserved features including the TFIIB-Recognition Element (BRE), approximately 5 nucleotides upstream (BREu) and 5 nucleotides downstream (BREd) of the TATA box. "

The TFIIB-DNA contact with the BREd takes place via the minor groove, while that with the upstream B recognition element (BREu) takes place through the major groove.

Transcription start sites
dBRE is cis-TATA box, between the TATA box and the Inr or transcription start site (TSS) and trans-TSS.

Hypotheses

 * 1) The dBRE is not involved in the transcription of A1BG.