What does CAP binding protein do?

Finally. After two days of ceaseless typing and meandering through excessive information, your new set of notes for lecture is ready for collection. Bio rep please collect on Mon morning... I am brain dead....almost.

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Finally can get down to reply to the loads of fan mail that lies before me and sort out a series of questions in my head.

Disclaimer: All info published are based on current understanding.


Function of CAP binding protein in lac operon:

Lac operon has a weak promoter (low in efficiency). When bound to DNA, CAP bp-cAMP complex will increase the affinity of promoter region for RNA polymerase - this is done through an almost 90 degrees bending of DNA which allow CAP to directly interact with the polymerase at the promoter.