Integration Host Factor: putting a twist on protein-DNA recognitionLynch, T.W., Read, E.K., Mattis, A.N., Gardner, J.F., Rice, P.A.
(2003) J Mol Biol 330: 493-502
- PubMed: 12842466
- DOI: https://doi.org/10.1016/s0022-2836(03)00529-1
- Primary Citation of Related Structures:
1OUZ, 1OWF, 1OWG
- PubMed Abstract:
Integration host factor (IHF) is a DNA-bending protein that recognizes its cognate sites through indirect readout. Previous studies have shown that binding of wild-type (WT)-IHF is disrupted by a T to A mutation at the center position of a conserved TTR motif in its binding site, and that substitution of betaGlu44 with Ala prevented IHF from discriminating between A and T at this position. We have determined the crystal structures and relative binding affinities for all combinations of WT-IHF and IHF-betaGlu44Ala bound to the WT and mutant DNAs. Comparison of these structures reveals that DNA twist plays a major role in DNA recognition by IHF, and that this geometric parameter is dependent on the dinucleotide step and not on the bound IHF variant.
Department of Biochemistry and Molecular Biology, The University of Chicago, 920 E 58th Street CLSC 221, Chicago, IL 60637, USA.