Lambda cro repressor complex with OR3 operator DNA. 19F nuclear magnetic resonance observations.

W J Metzler; P Lu

doi:10.1016/0022-2836(89)90372-0

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Lambda cro repressor complex with OR3 operator DNA. 19F nuclear magnetic resonance observations.

W J Metzler·P Lu

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Abstract

The interaction of lambda cro repressor with DNA is probed using synthetic 17 base-pair OR3 operators in which 5-fluorodeoxyuridine has been systematically incorporated at each of the nine positions normally occupied by a thymidine residue. By monitoring changes in chemical shift of the fluorine resonances upon cro repressor binding in aqueous buffers of varying 2H2O content, we have examined the specific cro repressor-OR3 DNA complex in detail. The results are interpreted in the context of the popular model for cro repressor-OR3 complex derived from the three-dimensional structure of the cro repressor in the absence of DNA. The results presented here not originally predicted by the model are: (1) there is an asymmetry in the environment at the two ends of the operator, although the base-pairs involved and the cro repressor dimer are symmetric; (2) there appears to be distortion of the DNA helix at two distinct positions; (3) changes of the DNA environment in the middle of the helix suggest additional DNA distortion not near the contact areas proposed in the model.

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Bacteriophage lambda DNA Probes DNA, Viral DNA-Binding Proteins Escherichia coli Fluorine Macromolecular Substances Magnetic Resonance Spectroscopy Models, Genetic Operator Regions, Genetic Repressor Proteins Transcription Factors Viral Proteins Viral Regulatory and Accessory Proteins Journal Article Research Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

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W J Metzler, P Lu. 1989-01-05. Lambda cro repressor complex with OR3 operator DNA. 19F nuclear magnetic resonance observations.. https://doi.org/10.1016/0022-2836(89)90372-0

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