Navigation Links
Promoter


for disambiguation of the term promoter, see the promoter Wiktionary article

In genetics, a promoter is a DNA sequence that enables a gene to be transcribed. The promoter is recognized by RNA polymerase, which then initiates transcription. In RNA synthesis, promoters are a means to demarcate which genes should be used for messenger RNA creation - and, by extension, control which proteins the cell manufactures.

The perfect promoter is called a canonical sequence.

Contents

Promoter elements

  • Core promoter
    • Transcription Start Site (TSS)
    • Approximately -35
    • A binding site for RNA polymerase
      • RNA-polymerase I: transcribes genes encoding ribosomal RNA
      • RNA-polymerase II: transcribes genes encoding mRNA and certain small nuclear RNAs
      • RNA-polymerase III: transcribes genes encoding tRNAs and other small RNAs
    • General transcription factor binding sites
  • Proximal promoter
    • Approximately -250
    • Specific transcription factor binding sites
  • Distal promoter
    • Anything further upstream (but not an enhancer or other regulatory region whose influence is positional/orientation independent)
    • Specific transcription factor binding sites

Promoters represent critical elements that can work in concert with other regulatory regions (enhancers, silencers, boundary elements /insulators) to direct the level of transcription of a given gene.

Promoter sequences

Prokaryotic promoters

In prokaryotes, the promoter consists of two short sequences at -10 and -35 position upstream of the gene, that is, prior to the gene in the direction of transcription. The sequence at -10 is called the Pribnow box and usually consists of the six nucleotides TATAAT. The Pribnow box is absolutely essential to start transcription in prokaryotes. The other sequence at -35 usually consists of the six nucleotides TTGACA. Its presence allows a very high transcription rate.

   <-- upstream                                                          downstream 
5'-XXXXXXXPPPPPXXXXXXPPPPPPXXXXGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGXXXX-3'
           -35       -10       Gene to be transcribed


Probability of occurrence of each nucleotide

 T    A    T    A    A    T
77%  76%  60%  61%  56%  82%
 T    T    G    A    C    A
69%  79%  61%  56%  54%  54%

Eukaryotic promoters

See Michael Levine and Robert Tjian. "Transcription regulation and animal diversity". Nature 424, 147 - 151 (10 July 2003) [1]

Binding

The binding of a promoter sequence (P) to a sigma factor-RNAP complex (R) is a two step process:

  1. R+P ↔ RP(closed). K = 10E7
  2. RP(closed) RP(open). K = 10E-2

Diseases Associated with Aberrant Promoter Function

Though OMIM is a major resource for gathering information on the relationship between mutations and natural variation in gene sequence and susceptibility to hundreds of diseases, it requires a sophisticated search strategy to extract those diseases that are associated with defects in transcriptional control where the promoter is believed to have direct involvement. This is a list of diseases that evidence suggests have some involvement of promoter malfunction, either through direct mutation of a promoter sequence or mutation in a transcription factor or transcriptional co-activator . Keep in mind that most diseases are heterogenous in etiology, meaning that one "disease" is often many different diseases at the molecular level, though the symptoms exhibited and the response to treatment might be identical. How diseases respond differently to treatment as a result of differences in the underlying molecular origins is partially addressed by the discipline of pharmacogenomics.


'"/>


(Date:12/19/2014)... --Research and Markets ( http://www.researchandmarkets.com/research/8kmfcn/iphone_5s ) ... 5S Fingerprint Sensor - Apple/AuthenTec TMDR92 & Sapphire ... http://photos.prnewswire.com/prnh/20130307/600769 ... 2012, Apple introduced the fingerprint reading feature with ... device of Apple incorporating such a feature, called ...
(Date:12/17/2014)... 2014 The Defense Logistics Agency is ... detect and prevent counterfeit microcircuits from entering into ... started performing an in-house microcircuit anti-counterfeit initiative dubbed ... of purchased microcircuits while increasing their reliability throughout ... will be conducted at DLA,s Electronics Product Test ...
(Date:12/15/2014)... 12, 2014 Research and Markets ... the "Global Facial Recognition Market 2015-2019" ... http://photos.prnewswire.com/prnh/20130307/600769 Facial recognition is ... Facial recognition system measures the overall facial feature ... mouth, and the distance between eyes. Facial recognition ...
Breaking Biology News(10 mins):iPhone 5S Fingerprint Sensor - Apple/AuthenTec TMDR92 & Sapphire - Technology Report 2Defense Logistics Agency Launches DNA Marking Capability to Strengthen Microcircuit Supply Chain 2Defense Logistics Agency Launches DNA Marking Capability to Strengthen Microcircuit Supply Chain 3Global Facial Recognition Market 2015-2019: Key Vendors are 3M Cogent, Cognitec Systems, NEC and Safran Group 2Global Facial Recognition Market 2015-2019: Key Vendors are 3M Cogent, Cognitec Systems, NEC and Safran Group 3
... in research to support energy efficiency policy and contribute to ... was unveiled today. Five new End Use Energy ... of energy use across society and how energy can be ... 26 million funding from two research councils, the Engineering and ...
... broad genetic landscape mapped of a Burkitt lymphoma tumor, ... mutations, including several that had not previously been associated ... to the disease. Findings from the genetic sequencing ... be used to develop new drugs or aim existing ...
... infectious diseases of humans come from animals. International health ... humans and livestock, not for companion dogs and cats. ... monitor infectious diseases of companion dogs and cats. The ... the School of Veterinary Sciences at the University of Bristol ...
Cached Biology News:£39 million for UK energy efficiency research to cut carbon use 2£39 million for UK energy efficiency research to cut carbon use 3£39 million for UK energy efficiency research to cut carbon use 4Duke Medicine news -- Genome sequencing of Burkitt Lymphoma reveals unique mutation 2Call for global monitoring of infectious diseases in dogs and cats 2
Other biology definitionOther Tags