The DNA sequences shown below are from the promoter regions of six bacterial genes. In each case, the last nucleotide in the sequence (highlighted in blue) is the  nucleotide that initiates transcription. Examine these sequences and identify the Pribnow box sequence at approximately -10 for each promoter.

Key Concepts

Pribnow Box

The Pribnow box, also known as the -10 region, is a conserved sequence found in bacterial promoters, typically located about 10 nucleotides upstream of the transcription start site. It is characterized by the consensus sequence 'TATAAT' and plays a crucial role in the initiation of transcription by providing a binding site for RNA polymerase and transcription factors.

Transcription Initiation

Transcription initiation is the process by which RNA polymerase binds to a promoter region of DNA and begins synthesizing RNA. This process involves the recognition of specific sequences, such as the Pribnow box, which facilitate the assembly of the transcription machinery and the unwinding of DNA to expose the template strand for RNA synthesis.

Bacterial Gene Regulation

Bacterial gene regulation involves mechanisms that control the expression of genes in response to environmental changes. Promoter sequences, including the Pribnow box, are critical for this regulation, as they determine when and how efficiently a gene is transcribed, influencing the production of proteins necessary for the bacterium's adaptation and survival.