Dictionary > Pribnow box

Pribnow box

Pribnow box –>
promoter
(Science: molecular biology) A region of dNA to which rNA polymerase binds before initiating the transcription of DNA into rNA.
The nucleotide at which transcription starts is designated -1 and nucleotides are numbered from this with negative numbers indicating upstream nucleotides and positive downstream nucleotides.
most bacterial promoters contain two consensus sequences that seem to be essential for the binding of the polymerase. The first, the pribnow box, is at about 10 and has the consensus sequence 5′ TATAAT 3′. The second, the 35 sequence, is centred about 35 and has the consensus sequence 5′ TTGACA 3′.
most factors that regulate gene transcription do so by binding at or near the promoter and affecting the initiation of transcription. Much less is known about eukaryote promoters, each of the three rNA polymerases has a different promoter.
rNA polymerase I recognises a single promoter for the precursor of rRNA.
rNA polymerase II, that transcribes all genes coding for polypeptides, recognises many thousands of promoters. most have the Goldberg Hogness or tATA box that is centred around position 25 and has the consensus sequence 5′ TATAAAA 3′. Several promoters have a cAAT box around 90 with the consensus sequence 5′ GGCCAATCT 3′. There is increasing evidence that all promoters for housekeeping genes contain multiple copies of a gC rich element that includes the sequence 5′ GGGC
731
GG 3′. Transcription by polymerase II is also affected by more distant elements known as enhancers.
rNA polymerase III synthesises 5s ribosomal RNA, all tRNAs and a number of small rNAs. The promoter for RNA polymerase III is located within the gene either as a single sequence, as in the 5s RNA gene or as two blocks, as in all tRNA genes.


You will also like...

Plant biology
Plant Biology

Plantlife can be studied at a variety of levels, from the molecular, genetic and biochemical level through organelles, c..

Pink Lotus plant on a pond
Freshwater Lentic Communities & Animals

This tutorial looks at some of the communities in freshwater lentic habitats. For instance, symbiosis occurs in a commun..

Balanced Diet
A Balanced Diet – Minerals and Proteins

Proteins and minerals can be derived from various dietary sources. They are essential for the proper growth and developm..

Gene Regulation in Eukaryotes
Gene Regulation in Eukaryotes

Learn about the general structure of a eukaryotic gene, the transcription factors, and post-transcriptional regulation....

green plant cells
Plant Cells vs. Animal Cells

Plant cells have plastids essential in photosynthesis. They also have an additional layer called cell wall on their cell..

Carbohydrates, fats and proteins - dietary sources
A Balanced Diet – Carbohydrates and Fat

Apart from vitamins, the human body also requires high energy sources such as carbohydrates and fats. If you want an ove..

Related Articles...

No related articles found

See all Related Topics