Isolation of human DNA sequences that bind to nuclear factor I, a host protein involved in adenovirus DNA replication.

Abstract

Nuclear factor I is a 47,000-dalton protein isolated from human cervical carcinoma HeLa cells that is required for the in vitro replication of adenovirus DNA. This protein was previously shown to bind specifically to nucleotides 17-48 of the left-hand terminus of cloned adenovirus serotype 5 DNA. An in vitro assay for DNA sequences that compete with adenovirus DNA for the binding of nuclear factor I was developed. With this assay, specific binding of human DNA sequences to nuclear factor I was shown. Using the DNA binding activity of nuclear factor I, segments of human DNA that bind tightly to this protein were isolated and cloned. One nuclear factor I binding site is present about every 100,000 base pairs in the HeLa cell genome. The binding of these DNA molecules to nuclear factor I resembles the binding of cloned adenovirus DNA to the protein and is resistant to high ionic strength. The isolation of DNA sequences from HeLa cells that bind specifically to nuclear factor I suggests that this protein interacts with host DNA in vivo.