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 Article
Opposite allosteric mechanisms in TetR and CAP
Jennifer E. Seedorff 1, Michael E. Rodgers 2, Robert Schleif 2 *
1Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218
2Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218
email: Robert Schleif (schleif@jhu.edu)

*Correspondence to Robert Schleif, Department of Biology, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218-2685

Funded by:
 NIH; Grant Number: GM018277

Keywords
Tet Repressor • CAP • CRP • allostery • DNA-binding protein • half-site operator • extrinsic allosteric mechanism • intrinsic allosteric mechanism

Abstract
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.

Received: 30 October 2008; Revised: 22 January 2009; Accepted: 28 January 2009

Digital Object Identifier (DOI)

10.1002/pro.88  About DOI