Fig. 7. Binding of Foxa2 to Hoxa5, Lim1 and Gsc homeoproteins through its Forkhead box domain. (A) ³⁵S-labeled homeoproteins Hoxa5, Gsc, Lim1, and Engrailed (En2), as well as ³⁵S-labeled Krox20 were incubated with immobilized GST or GST-Foxa2. All four homeoproteins bind Foxa2 but Krox20 does not. Positions of molecular mass markers (in kDa) are indicated on the left. (B) Mapping of the domain of Foxa2 involved in its interaction with Hoxa5, Gsc and Lim1. ³⁵S-labeled Forkhead box domain (148-257) and its flanking N-terminal (1-148) and C-terminal (257-458) domains were challenged for binding to GST-Hoxa5, GST-Gsc and GST-Lim1. In all three cases, only the Forkhead box domain of Foxa2 binds to the homeoprotein.