Transcription

Although each promoter is unique, most share a few common sequence

elements called

consensus sequences

Prokaryotic promoters share 2 main types of consensus sequences

- ________(aka Pribnow box) – found 10

10

RNA polymerase enzyme makes ______

_______ with the promoter at these

consensus sequences

RNA; binds

β, β’, α subunits interact and form the

core enzyme

σ factor controls binding to the promoter

specificity

Analogy

σ factor is the general, the core enzyme is the troops

Bacteria make many ______________of sigma factors

different

Examples of σ70 and σ54

σ70 – controls transcription of general purpose genes

σ54 – controls transcription of genes only during nitrogen starvation