Myosin MyTH4-FERM structures highlight important principles of convergent evolution

Significance

Myosins containing MyTH4-FERM (myosin tail homology 4-band 4.1, ezrin, radixin, moesin, or MF) domains in their tails are found in wide range of phylogenetically divergent organisms. Interestingly, evolutionarily distant MF myosins have similar roles in the extension of actin-filled membrane protrusions, such as filopodia, and microtubule binding, suggesting that their core functions have been highly conserved over evolution. A structural analysis of mammalian and Dd myosin MF domains in combination with comparison of diverse MF myosin sequences illustrate how tuning of existing features can give rise to new structures while preserving the general properties of myosin tails. Thus, tinkering with the MF domain enables it to serve as a multifunctional platform for cooperative recruitment of various partners, allowing common properties to arise through convergent evolution.