[Answer] What is myosin?

Answer: Thick filament protein with a head and elongated tail the heads form cross bridges with the thin filaments during muscle contraction
What is myosin?

Myosins are a superfamily of motor proteins best known for their roles in muscle contraction and in a wide range of other motility processes in eukaryotes. They are ATP-dependent and responsible for actin-based motility. The term was originally used to describe a group of similar ATPases found in the cells of both striated muscle tissue and smooth muscle tissue. Following the discovery by Pollard and Korn …

Myosins are a superfamily of motor proteins best known for their roles in muscle contraction and in a wide range of other motility processes in eukaryotes. They are ATP-dependent and responsible for actin-based motility. The term was originally used to describe a group of similar ATPases found in the cells of both striated muscle tissue and smooth muscle tissue. Following the discovery by Pollard and Korn (1973) of enzymes with myosin-like function in Acanthamoeba castellanii a global range of divergent myosin genes have been discovered throughout the realm of eukaryotes. Although myosin was originally thought to be restricted to muscle cells (hence myo-(s) + -in) there is no single “myosin”; rather it is a very large superfamily of genes whose protein products share the basic properties of actin binding ATP hydrolysis (ATPase enzyme activity) and force transduction. Virtually all eukaryotic cells contain myosin isoforms. Some isoforms have specialized functions in certain cell types (such as muscle) while other isoforms are ubiquitous. The structure and function of myosin is globally conserved across species to the extent that rabbit muscle myosin II will bind to actin from an amoeba.

Domains Most myosin molecules are composed of a head neck and tail domain. • The head domain binds the filamentous actin and uses ATP hydrolysis to generate force and to “walk” along the filament towards the barbed (+) end (with the exception of myosin VI which moves t…

Domains Most myosin molecules are composed of a head neck and tail domain. • The head domain binds the filamentous actin and uses ATP hydrolysis to generate force and to “walk” along the filament towards the barbed (+) end (with the exception of myosin VI which moves towards the pointed (-) end). • the neck domain acts as a linker and as a lever arm for transducing force generated by the catalytic motor domain. The neck domain can also serve as a binding site for myosin light chains which are distinct proteins that form part of a macromolecular complex and generally have regulatory functions. • The tail domain generally mediates interaction with cargo molecules and/or other myosin subunits . In some cases the tail domain may play a role in regulating motor activity. Power stroke Multiple myosin II molecules generate…

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