GFI and GFII are abundant DNA-binding proteins in the yeast Saccharomyces cerevisiae. Binding sites for GFI conform to the sequence 5'-RTCRYNNNNNACG-3'. This consensus can also accommodate the recognition sequence for the ARS1-binding factor ABFI. Results of retardation-competition assays, limited proteolysis experiments, molecular weight determinations based on denaturation-renaturation procedures and mobility shift assays of protein-DNA complexes formed in the presence of a monoclonal antibody raised against ABFI suggest strongly that GFI and ABFI are the same protein. Similarly, GFII appears to be identical to the centromere-binding protein CPF1 (alias CP1), since both proteins bind to the CDEI motif of yeast centromeres (5'-RTCACRTG-3') and cannot be detected in a cpf1 disruption mutant yeast strain. In addition, based on denaturation-renaturation studies, both factors appear to have molecular weights in the same range of 53-62 kDa.