title: Site-specific DNA binding of nuclear factor I: analyses of cellular binding sites.
abstract: Nuclear factor I is a cellular site-specific DNA-binding protein required for the efficient in vitro replication of adenovirus DNA. We have characterized human DNA sequences to which nuclear factor I binds. Three nuclear factor I binding sites (FIB sites), isolated from HeLa cell DNA, each contain the sequence TGG(N)6-7GCCAA. Comparison with other known and putative FIB sites suggests that this sequence is important for the binding of nuclear factor I. Nuclear factor I protects a 25- to 30-base-pair region surrounding this sequence from digestion by DNase I. Methylation protection studies suggest that nuclear factor I interacts with guanine residues within the TGG(N)6-7GCCAA consensus sequence. One binding site (FIB-2) contained a restriction endonuclease HaeIII cleavage site (GGCC) at the 5' end of the GCCAA motif. Digestion of FIB-2 with HaeIII abolished the binding of nuclear factor I. Southern blot analyses indicate that the cellular FIB sites described here are present within single-copy DNA in the HeLa cell genome.
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D004261:DNA Replication; D004277:DNA, Single-Stranded / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003850:Deoxyribonuclease I; D005260:Female; D006367:HeLa Cells; D006801:Humans; D008745:Methylation; D013329:Structure-Activity Relationship; D013463:Sulfuric Acid Esters
chemical_list: D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D013463:Sulfuric Acid Esters; D003850:Deoxyribonuclease I; C007482:dimethyl sulfate