PMID: 12842466 , Related PDB ids: 1OUZ, 1OWF, 1OWG

Authors:

Lynch TW, Read EK, Mattis AN, Gardner JF, Rice PA

Title:

Integration host factor: putting a twist on protein-DNA recognition.

Journal:

J Mol Biol. 2003 Jul 11;330(3):493-502.

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.