Cross-bridge cycling myosin isoforms

Table I illustrates the variability of the amino-terminal residues of several different actin isoforms. Mutagenesis in this region can result in partial or complete inhibition of F-actin motility (Sutoh, 1993), consistent with the site being a likely initial target for myosin during the cross-bridge cycle (Rayment et al., 1993b). In fact, numerous studies also have identified several domains of the actin molecule representing clusters of amino acids specifically involved in monomer-monomer interactions (Holmes et al., 1990 Hennessey et al., 1993 Khaitlina et al., 1993 Labbe et al., 1994), actin-myosin interactions (Holmes and Kabsch, 1991 Hennessey et al., 1993 Schroder et al.,...

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