Structure of the DAX-1 protein. (a) Schema of the human DAX-1 protein. The N-terminal repeats are indicated with arrows, together with the last incomplete repeat that extends into the C-terminal domain. The position and sequence of the LXXLL motifs in the N-terminal domain as well as the conserved motif in the C-terminal domain are shown. (b) The three-dimensional structure of the Dax-1:LRH-1 complex. LRH-1 is shown in yellow; the two Dax-1 molecules are shown in blue. The structural elements involved in the binding of the first Dax-1 to LRH-1 are shown in rose (RH site) and dark red (AF-2 region). The structural elements at the second Dax-1:LRH-1 interface are indicated in light and dark green. From [61]. Copyright 2008 National Academy of Sciences, USA.