Studies on Divergent Crp-dependent Promoters

Bacterial genomes contain genes that are packed closely together. For many genes, promoter regions overlap, and regulatory segments that carry divergent promoters are common. In this study, I have focussed on promoters that are regulated by the cyclic AMP receptor protein (CRP) of Escherichia coli. CRP is a global regulator that directs the activity of more than 100 genes, some of which are oriented back-to-back, i.e., in a divergent fashion. CRP is known to activate transcription initiation through direct protein-protein contact with RNA polymerase and CRP-dependent promoters are classified into two classes, Class I and Class II, according to the location of the CRP-binding site. I have investigated whether a single bound CRP, either at a Class I or a Class II location, can activate divergent transcription.