CRP:cAMP complex binding to the lac operator region induces a structural change in lac DNA.
Changes in DNA structure induced by cAMP receptor protein (CRP) binding to the lac-control region contained on a 231 bp fragment were investigated by measurement of the molar cyclization factor (jM). Increases in jM were observed at low to moderate CRP: cAMP complex concentrations and correlated with CRP binding to the promoter-proximal CRP binding site. At CRP:cAMP complex concentrations greater than 200 nM, decreases in jM correlated with CRP binding to both the promoter-proximal and the operator-proximal CRP binding sites. These results show that binding of the CRP:cAMP complex to the operator-proximal CRP binding site induces a structural change in lac DNA.
Gang
J B
JB
Department of Chemistry, Kyungwon University, Sungnam, Korea.
Harman
J G
JG
D001665:Binding Sites / Q000235:genetics; D000242:Cyclic AMP / Q000378:metabolism*; D002373:Cyclic AMP Receptor Protein / Q000378:metabolism*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D007763:Lac Operon; D015394:Molecular Structure; D011401:Promoter Regions, Genetic
D002373:Cyclic AMP Receptor Protein; D004269:DNA, Bacterial; D000242:Cyclic AMP