Fig. 1. A molecular model showing the location of the GFP fusion to the myosin motor domain. This ribbon representation of the myosin motor domain (blue) and GFP (green) illustrates the linkage (arrowhead) of the C terminus of GFP to the N terminus of myosin. This model illustrates the important functional sites on the myosin motor domain in relation to the GFP attachment point. The three point mutations in the motor domain (R403Q, R453C and G584R) are identified with CPK models (red) of the WT residues. The essential light chain (yellow) and the regulatory light chain (magenta) are bound to the myosin lever arm. Model coordinates are for adult pectoralis muscle myosin subfragment-1 (Rayment et al., 1993) and GFP (Yang et al., 1996).