What is the purpose of a sigma factor in prokaryotic transcription?

Prokaryotic transcription can create polycistronic mRNA.

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.

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. Determine the consensus sequence for the Pribnow box from these sequences.

Describe the two types of transcription termination found in bacterial genes. How does transcription termination differ for eukaryotic genes?

Draw a bacterial promoter and label its consensus sequences. How does this promoter differ from a eukaryotic promoter transcribed:

By RNA polymerase II?

By RNA polymerase I?

By RNA polymerase III?

The segment of the bacterial TrpA gene involved in intrinsic termination of transcription is the following:

3'-TGGGTCGGGGCGGATTACTGCCCCGAAAAAAAACTTG-5'

5'-ACCCAGCCCCGCCTAATGACGGGGCTTTTTTTTGAAC-3'

Label the template and coding DNA strands.

The segment of the bacterial TrpA gene involved in intrinsic termination of transcription is the following:

3'-TGGGTCGGGGCGGATTACTGCCCCGAAAAAAAACTTG-5'

5'-ACCCAGCCCCGCCTAATGACGGGGCTTTTTTTTGAAC-3' Draw the mRNA structure that forms during transcription of this segment of the TrpA gene.