Electrophoretic mobility shift assays demonstrating specific binding of SCL/Tal-1 and a GATA factor to the

Flk-1 minimal enhancer. SCL/Tal-1–containing complexes interact with SCL/Tal-1 motifs at bp 232 (A) and at bp 358 (B), and a GATA factor interacts with the GATA motif at bp 72 (C) of the minimal enhancer. Antis indicates antiserum; comp, competitor oligonucleotide; W, wild-type; M, mutant.