Structure of the actin-myosin interface.
The topography of the rigor complex between F-actin and myosin heads (S1) has been investigated by carbodiimide zero-length cross-linking. The results demonstrate for the first time that the 95,000-molecular weight (95K) heavy chain of the myosin head enters into van der Waals contact with two neighbouring actin monomers; one is bound to the 50K domain and the other to the 20K domain of the myosin chain. The covalent F-actin-S1 complex can be isolated; it shows a vastly elevated Mg2+-ATPase. Each pair of actin subunits in the thin filament seems to act as a functional unit for specific binding of a myosin head and stimulation of its Mg2+-ATPase activity.
D000199:Actins / Q000378:metabolism*; D000205:Actomyosin / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D017301:Ca(2+) Mg(2+)-ATPase; D007700:Kinetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D009218:Myosins / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation
D000199:Actins; D046911:Macromolecular Substances; D000205:Actomyosin; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; D009218:Myosins