THE MYOSIN FILAMENT

The Myosin Filament

The subunit organization of the myosin filament of chicken striated muscle has been observed directly in cross-sections in electron microscopy. The organization consists of three centrally located and nine peripherally located subunits in a close-packed arrangement. This arrangement is that predicted by a previously derived model for the detailed molecular organization of the myosin filament (P...

Mapping the actin filament with myosin.

Structural studies have shown that the heads of the myosin motor molecule bind preferentially to "target zones" of favorably oriented sites on the helices of the actin filament. We present direct evidence for target zones from the interactions of a single myosin head with an actin filament held between two optically trapped beads. With compliant traps, thermal motions of the filament allow the ...

Myosin filament structure in vertebrate smooth muscle

The in vivo structure of the myosin filaments in vertebrate smooth muscle is unknown. Evidence from purified smooth muscle myosin and from some studies of intact smooth muscle suggests that they may have a nonhelical, side-polar arrangement of crossbridges. However, the bipolar, helical structure characteristic of myosin filaments in striated muscle has not been disproved for smooth muscle. We ...

Slime Mold Myosin Thick Filament Assembly Dissected

THE MYOSIN FILAMENT IV. Observation of the Internal Structural Arrangement

The subunit organization of the myosin filament of chicken striated muscle has been observed directly in cross-sections in electron microscopy . The organization consists of three centrally located and nine peripherally located subunits in a close-packed arrangement . This arrangement is that predicted by a previously derived model for the detailed molecular organization of the myosin filament ...