Enables cytoskeletal motor activity. Acts upstream of or within smooth muscle contraction. Located in brush border; smooth muscle contractile fiber; and stress fiber. Part of muscle myosin complex. Is expressed in several structures, including alimentary system; brain; cardiovascular system; genitourinary system; and liver and biliary system. Human ortholog(s) of this gene implicated in patent ductus arteriosus and thoracic aortic aneurysm. Orthologous to human MYH11 (myosin heavy chain 11). [provided by Alliance of Genome Resources, Apr 2022]