Interaction between the adenovirus DNA-binding protein and double-stranded DNA.

DNA-binding protein was characterized by previous investigators as a single-stranded DNA-binding protein analogous to the gene 32 protein of phage T4 (Van der Vliet &; Levine, 1973; Sugawara et al., 1977). In the studies presented here the interactions between natural and synthetic polynucleotides and the DNA-binding protein of adenovirus 2-infected HeLa cells have been examined. Polynucleotide melting techniques revealed a tight yet dissociable binding to the helix structure of double-stranded DNA. In addition, binding and filter binding competition experiments at high DNA to protein ratios revealed a specific binding to double-stranded DNA termini with a dissociation constant of 1 × 10^?9 to 2 × 10^?9m. The ability of DNA-binding protein to bind to heat-denatured viral DNA was confirmed but the binding to double-stranded DNA termini was more specific on a molar basis. DNA-binding protein can recognize both flush and staggered ends of double-stranded DNA molecules.