Kinetic analysis of nuclear factor I and its DNA‐binding domain with the adenovirus origin of replication

Nuclear factor I (NFI) is the collective name for a heterogeneous group of proteins, purified from HeLa cells, which stimulate the initiation of adenovirus type 2 DNA replication on binding to the adenovirus origin of replication. Protease treatment of NFI reduced all DNA‐protein complexes to a single NFI‐DNA complex, suggesting that they share a common DNA‐binding domain. We present here a comparison of rate constants for the interaction of the full‐length NFI protein and the core DNA‐binding domain with their recognition site in the replication origin. The results demonstrate that the core protein alone can bind efficiently to the recognition site and that amino acid sequences outside this domain appear to have minor influence over the binding kinetics of NFI.