Question

Describe the function(s) of a PROMOTER.

Answer 1

Ans. A promoter is a sequence of nucleotides in a DNA molecule to start the process of transcription. It is the region where transcription factors bind to start the process of transcription of DNA into mRNA. Promoter region lies towards the 5' end of the DNA strand near the site of transcription initiation (+1 site) and it controls the expression of gene downstream of it. Promoter is the regulatory sequence found in both prokaryotes and eukaryotes. When the promoter is inhibited from binding to RNA Polymerase then transcription can not take place. Promoter can be weak or strong promoter. A weak promoter allows low transcription level and hence less protein production. It shows a promoter, even though gene expression is there, regulate the level of expression of proteins from the gene.