A homology domain shared between Drosophila optomotor-blind and mouse Brachyury is involved in DNA binding.

The distribution of sequence elements divides the optomotor-blind protein into three regions and is suggestive of a transcriptional regulatory role of this protein. The central region of Omb is homologous to the N-terminal half of the Brachyury protein. The conserved domain of Omb is here shown to possess general DNA binding affinity but has no significant similarity to recognized DNA binding motifs.