Opposite allosteric mechanisms in TetR and CAP.
Regulation of the DNA binding affinity of an oligomeric protein can be considered to consist of an intrinsic component, in which the affinity of an individual DNA-binding domain is modulated in response to effector binding, and an extrinsic component, in which the relative position of the protein's two DNA-binding domains are altered so that they can or cannot contact both half-site operators simultaneously. We demonstrated directly that the TetR repressor utilizes an extrinsic mechanism and CAP, the catabolite activator protein, utilizes an intrinsic mechanism.
Seedorff
Jennifer E
JE
Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, USA.
Rodgers
Michael E
ME
Schleif
Robert
R
D000494:Allosteric Regulation; D000242:Cyclic AMP / Q000378:metabolism*; D002373:Cyclic AMP Receptor Protein / Q000737:chemistry / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D012097:Repressor Proteins / Q000737:chemistry / Q000378:metabolism*; D013752:Tetracycline / Q000378:metabolism*
D002373:Cyclic AMP Receptor Protein; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D012097:Repressor Proteins; C034811:tetracycline resistance-encoding transposon repressor protein; D004247:DNA; D000242:Cyclic AMP; D013752:Tetracycline