title: Sequence-specific interactions of the tight-binding I12-X86 lac repressor with non-operator DNA.
abstract: The tight-binding I12-X86 lac repressor binds to non-operator DNA in a sequence-specific fashion. Using the DNA of the E. coli I gene we have investigated these sequence-specific interactions and compared them to the operator binding of wild-type repressor. The specific, non-operator DNA interactions are sensitive to the inducer IPTG. One strong binding site in the I gene DNA was found to be one of two expected on the basis of their homology with the lac operator. The binding of I12-X86 repressor to this site was visualized using the footprinting technique, and found to be consistent with an operator-like binding configuration. The protection pattern extends into an adjacent sequence suggesting that two repressor tetramers are bound in tandem.
mesh_terms: D001345:Autoradiography; D001483:Base Sequence; D004269:DNA, Bacterial / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D007763:Lac Operon; D012097:Repressor Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D012097:Repressor Proteins; D014157:Transcription Factors