DNA Looping Generated by DNA Bending Protein IHF and the Two Domains of Lambda Integrase

• DOI: 10.1126/science.2544029
• Publication Date: 2006-10-05T21:21:28Z
• Authors: Lina Moitoso de V...; Sunghoon Kim; Arthur Landy
• Keywords: DNA, Bacterial; Integration Host Factors; Recombination, Genetic; 0303 health sciences; Binding Sites; Integrases; DNA Restriction Enzymes; Bacteriophage lambda; DNA-Binding Proteins; 03 medical and health sciences; Bacterial Proteins; DNA Nucleotidyltransferases; DNA, Viral; Mutation; DNA Transposable Elements; Nucleic Acid Conformation

The multiprotein-DNA complexes that participate in bacteriophage lambda site-specific recombination were used to study the combined effect of protein-induced bending and protein-mediated looping of DNA. The protein integrase (Int) is a monomer with two autonomous DNA binding domains of different sequence specificity. Stimulation of Int binding and cleavage at the low affinity core-type DNA sites required interactions with the high affinity arm-type sites and depended on simultaneous binding of the sequence-specific DNA bending protein IHF (integration host factor). The bivalent DNA binding protein is positioned at high affinity sites and directed, by a DNA bending protein, to interactions with distant lower affinity sites. Assembly of this complex is independent of protein-protein interactions.