There is considerable sequence homology between dystrophin and utrophi
n, both at the protein and DNA level, and consequently it was assumed
that their domain structures and functions would be similar, As more o
f the detailed biochemical and cell biological properties of these two
proteins become known, so it becomes clear that there are subtle if n
ot significant differences between them, We review recent findings and
present new hypotheses into the structural and functional properties
of the actin-binding domain, central coiled-coil region and regulatory
/membrane protein-binding regions of dystrophin and utrophin.