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Gene transcriptions/Elements/Downstream TFIIB recognitions

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The downstream B recognition element designated as the BREd,[1] or dBRE, is an additional core promoter element that occurs downstream of the TATA box and is recognized by general transcription factor II B.[1]

This image is of a gray slender loris (Loris lydekkerianus nordicus) from Northern Sri Lanka. Credit: Dr. K.A.I. Nekaris.

Consensus sequencesEdit

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'.[1]

Eukaryote genesEdit

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".[1]

Human genesEdit

GeneID: 9555 H2A histone family, member Y (H2AFY)[2] "contains a poor TATA element, but both a consensus Inr and DPE in addition to a six/seven match BREd."[1]

General transcription factor II BsEdit

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.[3]

General transcription factor II B can recognize two distinct sequence elements that flank the TATA box.[1] "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)."[1]

"[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.[4]"[5]

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.[1]

Transcription start sitesEdit

Main articles: Gene transcriptions/Start sites and Transcription start sites

dBRE is cis-TATA box, between the TATA box and the Inr or transcription start site (TSS) and trans-TSS.[1]

HypothesesEdit

Main article: Hypotheses
  1. The dBRE is not involved in the transcription of A1BG.

See alsoEdit

ReferencesEdit

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Wensheng Deng, Stefan G.E. Roberts (October 15, 2005). "A core promoter element downstream of the TATA box that is recognized by TFIIB". Genes & Development 19 (20): 2418–23. doi:10.1101/gad.342405. PMID 16230532. http://genesdev.cshlp.org/content/19/20/2418.full. 
  2. ↑ HGNC (February 10, 2013). "H2AFY H2A histone family, member Y [ Homo sapiens ]". Bethesda, MD, USA: National Center for Biotechnology Information, U.S. National Library of Medicine. Retrieved 2013-02-11.
  3. ↑ Tsai FTP, Sigler PB (2000). "Structural basis of preinitiation complex assembly on human Pol II promoters". EMBO J. 19: 25–36. 
  4. ↑ "Polymerase II".
  5. ↑ "RNA polymerase II holoenzyme, In: Wikipedia". San Francisco, California: Wikimedia Foundation, Inc. January 19, 2013. Retrieved 2013-02-11.

Further readingEdit

External linksEdit

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