DNA RECOGNITION PROPERTIES OF THE N-TERMINAL DNA-BINDING DOMAIN WITHIN THE LARGE SUBUNIT OF REPLICATION FACTOR-C

Replication Factor C (RFC) is a five-subunit protein complex required for eukaryotic DNA replication and repair. The large subunit within th is complex contains a C-terminal DNA binding domain which provides spe cificity for PCNA loading at a primer-template and a second, N-termina l DNA binding domain of unknown function. We isolated the N-terminal D NA binding domain from Drosophila melanogaster and defined the region within this polypeptide required for DNA binding. The DNA determinants most efficiently recognized by both the Drosophila minimal DNA bindin g domain and the N-terminal half of the human large subunit consist of a double-stranded DNA containing a recessed 5' phosphate. DNA contain ing a recessed 5' phosphate was preferred 5-fold over hairpined DNA co ntaining a recessed 3' hydroxyl, Combined with existing data, these DN A binding properties suggest a role for the N-terminal DNA binding dom ain in the recognition of phosphorylated DNA ends.