Does anyone know how the leucine-responsive regulatory protein works to regulate gene expression? From what I understand, in the pap operon in E. coli, it binds to a operator overlapping a Dam site. By blocking Dam, it prevents the expression of the papI promoter.

 

I don't understand how the protein functions, however. The paper I'm reading doesn't really go into detail about it.

I am not sure what your question is. Proteins of the Lrp-family bind DNA via a N-terminal HTH motif (pretty much standard in that regard). Generally, if you find that a particular paper is missing information that you need, try to track down a review. There are a couple around of LRP-type proteins. If you are interested what the Lrp-protein in E. coli does, there are number around describing its regulon (it is rather a global regulator IIRC).

Or are you actually interested in the particular mode of the Lrp-regulated Pap-pili switch? That is, how methylation is inhibited?