The B recognition element (BRE) is a

DNA sequence DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine. Th ...

found in the

promoter region In genetics, a promoter is a sequence of DNA to which proteins bind to initiate transcription of a single RNA transcript from the DNA downstream of the promoter. The RNA transcript may encode a protein (mRNA), or can have a function in and of i ...

of most genes in

eukaryote Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacte ...

s and

Archaea Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebac ...

. The BRE is a

cis-regulatory element ''Cis''-regulatory elements (CREs) or ''Cis''-regulatory modules (CRMs) are regions of non-coding DNA which regulate the transcription of neighboring genes. CREs are vital components of genetic regulatory networks, which in turn control morphoge ...

that is found immediately near

TATA box In molecular biology, the TATA box (also called the Goldberg–Hogness box) is a sequence of DNA found in the core promoter region of genes in archaea and eukaryotes. The bacterial homolog of the TATA box is called the Pribnow box which has ...

, and consists of 7

nucleotide Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules wi ...

s. There are two sets of BREs: one (BREu) found immediately upstream of the TATA box, with the consensus SSRCGCC; the other (BREd) found around 7 nucleotides downstream, with the consensus RTDKKKK. The BREu was discovered in 1998 by Richard Ebright and co-workers. The BREd was named in 2005 by Deng and Roberts; such a downstream recognition was reported earlier in 2000 in Tsai and Sigler's crystal structure.

Binding

The

transcription factor II B Transcription factor II B (TFIIB) is a general transcription factor that is involved in the formation of the RNA polymerase II preinitiation complex (PIC) and aids in stimulating transcription initiation. TFIIB is localised to the nucleus and pro ...

(TFIIB) recognizes either BRE and binds to it. Both BREs work in conjunction with the TATA box (and TATA box binding protein), and have various effects on levels of transcription. TFIIB uses the cyclin-like repeats to recognize DNA. The C-terminal

alpha helices The alpha helix (α-helix) is a common motif in the secondary structure of proteins and is a right hand-helix conformation in which every backbone N−H group hydrogen bonds to the backbone C=O group of the amino acid located four residues ear ...

of TFIIB intercalate with the

major groove Major (commandant in certain jurisdictions) is a military rank of commissioned officer status, with corresponding ranks existing in many military forces throughout the world. When used unhyphenated and in conjunction with no other indicators ...

of the DNA at the BREu. The N-terminal helices bind to the minor groove at BREd. TFIIB is one part of the preinitiation complex that helps

RNA polymerase II RNA polymerase II (RNAP II and Pol II) is a multiprotein complex that transcribes DNA into precursors of messenger RNA (mRNA) and most small nuclear RNA (snRNA) and microRNA. It is one of the three RNAP enzymes found in the nucleus of eukaryoti ...

bind to the DNA. In addition to the human TFIIB-BRE structure, structures from many other organisms have been solved. Among those are transcription factor B (TFB) from the

archaeon Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebact ...

'' Pyrococcus woesei'' which presents an inverted orientation and a TFIIB from the parasite ''

Trypanosoma brucei ''Trypanosoma brucei'' is a species of parasitic Kinetoplastida, kinetoplastid belonging to the genus ''Trypanosoma'' that is present in sub-Saharan Africa. Unlike other protozoan parasites that normally infect blood and tissue cells, it is exclus ...

'' which despite some specific insertions show a similar fold.

Notes

References

Regulatory sequences {{genetics-stub

Binding

See also

Notes

References