A major level at which gene expression is controlled is at the level of transcription initiation. The earlier view that transcription initiation occurs at a single site for every gene is no longer valid as many genes have more than one site of transcription initiation and, therefore, more than one promoter. The use of alternative promoters is a versatile mechanism for creating diversity and flexibility in the regulation of gene expression.
Keywords: promoter; alternative promoter; gene expression; transcription initiation





