A phase variation control mechanism involving Pap B, Pap I, catabolite activator protein (CAP), leucine responsive regulatory protein (Lrp) and deoxyadenosine methylase (Dam) regulate the expression of pyelonephritis-associated pilus (Pap). This study centers on elucidating the role of Lrp in the transcription of Pap pilus. Specifically, we will measure the translocation of Lrp bound to plasmid DNA of Escherichia coli induced by Pap I. A hypothesis is that three Lrp dimers interact with the Pap I and translocate 102 base pairs from a GATC-II to a GATC-I sequence. In preparation for this measurement, we have obtained Atomic Force Microscopy (AFM) images that show Lrp bound to a particular binding site on DNA in buffer solution.