eukaryotic promoters

EUKARYOTIC PROMOTER

Presented by:Manish Gaud.Department: Pharmaco-Informatics(PI-291)NIPER HAJIPUR. 1

Eukaryotic PromotersIn genetics:A promoter is a DNA sequence that can recruit transcriptional machinery and lead to transcription of the downstream DNA sequence. Location:located near the transcription start sites of genes, on the same strand and upstream on the DNA (towards the 5' region of the sense strand). Size:Promoters can be about 100–1000 base pairs long.

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Importance of promoter• Promoter is a binding site for RNA polymerase.• RNA polymerase bind only on promoter.• It helps in transcription.• A promoter may include a binding site for a protein

presence or absence of that protein will affect the strength of the promoter. Such a promoter is known as a regulated promoter.

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•Three kind of RNA polymerase can bind on promoter…• RNA polymerase I • RNA polymerase II• RNA polymerase III

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Types of promoters• 1)Constitutive promoter :-• These promoters are always active for gene expression and

environment independent.

•2)Tissue-specific :-• These promoters direct the gene expression in a specific

tissues or at certain stage of development.

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Types of promoters•3)Synthetic promoter :-• These promoters are made by primary element of a

particular region from diverse origin.

•4)Inducible promoter :-• These promoters dependent upon the external stimuli &

environmental factors for gene expression .

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Method to determine promoter site.

•DNase footprint assay method:

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Online promoter prediction tools

• There are many online tools available for predicting promoter ..• For example,• Promoter 2.0 prediction server.• Neural Network Promoter Prediction.• PROMOSER.• Etc.

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•Promoter 2.0 Prediction Results

• gi_186429_gb_J00265.1_HUMINS01 Human insulin gene, complete 4044 nucleotides

• Position Score likelihood • 2300 1.118 Highly likely prediction • 2900 0.620 Marginal prediction • 3700 0.521 Marginal prediction

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