title: Examining the contribution of a dA+dT element to the conformation of Escherichia coli integration host factor-DNA complexes.
abstract: DNA binding proteins that induce structural changes in DNA are common in both prokaryotes and eukaryotes. Integration host factor (IHF) is a multi-functional DNA binding and bending protein of Escherichia coli that can mediate protein-protein and protein-DNA interactions by bending DNA. Previously we have shown that the presence of a dA+dT element 5'-proximal to an IHF consensus sequence can affect the binding of IHF to a particular site. In this study the contribution of various sequence elements to the formation of IHF-DNA complexes was examined. We show that IHF bends DNA more when it binds to a site containing a dA+dT element upstream of its core consensus element than to a site lacking a dA+dT element. We demonstrate that IHF can be specifically crosslinked to DNA with binding sites either containing or lacking this dA+dT element. These results indicate the importance of flanking DNA and a dA+dT element in the binding and bending of a site by IHF.
authors.affiliation: Department of Microbiology, University of Illinois, Urbana, 61801, USA.
authors.forename: L M
authors.initials: LM
authors.lastname: Hales
authors.forename: R I
authors.initials: RI
authors.lastname: Gumport
authors.forename: J F
authors.initials: JF
authors.lastname: Gardner
mesh_terms: D001287:Attachment Sites, Microbiological; D001426:Bacterial Proteins / Q000737:chemistry*; D001482:Base Composition; D001483:Base Sequence; D001665:Binding Sites; D003432:Cross-Linking Reagents; D004274:DNA, Recombinant / Q000737:chemistry / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry*; D004926:Escherichia coli / Q000737:chemistry; D034982:Integration Host Factors; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry* / Q000235:genetics; D011067:Poly dA-dT / Q000737:chemistry* / Q000235:genetics; D011995:Recombination, Genetic / Q000235:genetics; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins; D003432:Cross-Linking Reagents; D004274:DNA, Recombinant; D004268:DNA-Binding Proteins; D034982:Integration Host Factors; D009838:Oligodeoxyribonucleotides; D011067:Poly dA-dT