Myosin ATPase (EC 3.6.4.1) is an enzyme with systematic name ATP phosphohydrolase (actin-translocating). This enzyme catalyses the following chemical reaction Myosin ATPase (EC 3.6.4.1) is an enzyme with systematic name ATP phosphohydrolase (actin-translocating). This enzyme catalyses the following chemical reaction ATP hydrolysis provides energy for actomyosin contraction.