The diagram below shows a DNA duplex. The template strand is identified, as is the location of the  nucleotide.

Assume this region contains a gene transcribed in a bacterium. Identify the location of promoter consensus sequences and of the transcription termination sequence. <>

Key Concepts

Promoter Consensus Sequences

Promoter consensus sequences are specific DNA sequences located upstream of a gene that signal the start of transcription. In bacteria, these sequences are recognized by RNA polymerase and transcription factors, facilitating the binding of the enzyme to initiate RNA synthesis. Common elements include the -10 (Pribnow box) and -35 regions, which are crucial for the proper initiation of transcription.

Transcription Termination Sequence

The transcription termination sequence is a specific region of DNA that signals the end of transcription. In bacteria, this can involve a hairpin loop structure formed in the RNA transcript, which causes RNA polymerase to detach from the DNA. This sequence ensures that the RNA molecule is released and that transcription is properly concluded, preventing the synthesis of unnecessary RNA.

DNA Duplex Structure

The DNA duplex structure refers to the double-helix formation of DNA, consisting of two complementary strands held together by base pairs. Each strand has a directionality (5' to 3' and 3' to 5'), which is essential for processes like transcription and replication. Understanding this structure is vital for identifying functional regions such as promoters and termination sequences within the DNA.