A similar myosin, the conventional myosin
II isoform, was purified from Dictyostelium amoeba, and its actin-activated Mg-ATPase activity was modified by the phosphorylation mechanism.
Myosin II, also known as conventional myosin
, is vesicle-associated in extracts of clam (Spisula solidissima) oocytes [4, 13].
Of the two, HS1 is a myosin II null mutant that does not express conventional myosin
, which is responsible for production of major mechanochemical forces (7).
Based on different C-terminal cargo-binding domains, myosin superfamily members are classified into conventional myosins
(class II) and unconventional myosins (classes I and III-XV) [16-18].