This is quite a specific question, and I'm hoping someone might be able to assist in a literature hunt I've been engaged in for ages.
I study some long bacterial operons, and have noticed that the GC% content at the 3' end drops significantly compared to the beginning of the operon.
I vaguely recall hearing (I can't remember if it was from a paper or a lecture or something), that lower GC (higher AT) content can promote transcription. This sounds plausible to me since it promotes strand separation (this is how replicon origins are often defined), but I've tried several times to find a paper that might demonstrate/attest to this. The hypothesis therefore, is that the distal ends of the operon might have lower GC in order to enhance transcription as the influence of the 5' UTR promotor sequences etc being to wane over a distance.
Has anyone ever come across such a paper or has any information to confirm or deny this? Information to the contrary (e.g. high GC reduces transcription) would also suffice.