Abstact

GA-binding protein (GABP) is a transcriptional regulator composed of two structurally dissimilar subunits. The alpha subunit contains a DNA-binding domain that is a member of the ETS family, whereas the beta subunit contains a series of ankyrin repeats. The crystal structure of a ternary complex containing a GABPalpha/beta ETS domain-ankyrin repeat heterodimer bound to DNA was determined at 2. 15 angstrom resolution. The structure shows how an ETS domain protein can recruit a partner protein using both the ETS domain and a carboxyl-terminal extension and provides a view of an extensive protein-protein interface formed by a set of ankyrin repeats. The structure also reveals how the GABPalpha ETS domain binds to its core GGA DNA-recognition motif.