 This region of similarity can be divided into several functional domains such as two coiled-coil regions, two EF hands or a ZZ-type zinc finger.A phylogenic tree for the dystrophin protein family has been proposed based on the analysis of known dystrobrevin and dystrophin sequences that were extracted from human and fruit fly proteins.The phylogeny postulated a non-metazoan ancestor that had a single dystrophin/dystrobrevin protein, which probably functioned as a homodimer.