The homeodomain DNA-binding motif. This molecular structure shows the homeodomain motifs of the Drosophila transcription factor known as Paired, a dimeric protein (only a small part of the much larger Paired dimer is shown). The recognition helix in each subunit is stacked on two other α helices and can be seen protruding into the major groove. The N-terminal residues reach around the DNA and interact with the minor groove.