Evolutionary studies of myosin

Our observations suggest that the interacting heads motif is a common mechanism for switching off activity in myosin II across the animal kingdom. We tested this by comparing myosin molecules from the earliest animals (sponges) to mammals. We find the same structure in all cases: the folded myosin structure must have originated at the earliest times of evolution and be fundamental to myosin and motility (Jung et al., MBOC 2008; Lee et al., PNAS 2018; Alamo et al., Biophys. Revs. 2018). Comparison of thick filaments from different species leads to the same conclusion: the same motif is present in all species, from primitive invertebrates to vertebrates (Zoghbi et al., PNAS 2008; Zhao et al., JMB, 2009; Woodhead et al., PNAS 2013; Alamo et al., Biophys. Revs. 2017).  The early origin and high conservation implies that head-head interaction is crucial to muscle relaxation.  Our current research focuses on near-atomic resolution detail of the interaction by cryo-EM.