Biochemical properties of cbfβ protein.

(A) The cbfβ associates with human CBFα2. ³⁵S-labeled in vitro–translated human CBFβ (lanes 1 and 2) and zebrafish cbfβ (lanes 3 and 4) proteins were immunoprecipitated by an anti-CBFα2 antibody in the presence (lanes 2 and 4) or absence (lanes 1 and 3) of the CBFα2 protein and separated by electrophoresis. (B) The cbfβ enhances DNA binding by CBFα2. A ³²P-labeled oligonucleotide (HA) containing the recognition site for CBF was incubated with the in vitro–translated proteins and separated by electrophoresis. H₂O control, lane 5; in vitro translation lysate control, lane 6; human CBFα2 alone, lane 7; human CBFα2 plus CBFβ, lane 8; zebrafish cbfβ alone, lane 9; human CBFα2 plus zebrafish cbfβ, lane 10.