Question

Can someone explain what promoters are, the different types of promoters and what they do?

Answer 1

Promoters are specific sequences present upstream of transcription start site(TSS) in the sense strand. These sequences help assemble the RNA polymerase for transcription of a gene.

There are 4 types of promoters. Constitutive promoters, tissue-specific promoters, synthetic promoters and inducible promoters.

Consitutive promoters always express the gene and are environment independent.

Tissue-specific promoters express the genes in specific tissues in specific stage of development.

Synthetic promoters do not exist in nature and are made by genetic engineering for different types of expressions.

Inducible promoters are dependent on external stimuli and environmental factors for gene expression.