The enzyme is composed of three subunits. The holoenzyme dephosphorylates myosin light chains and EC 2.7.11.18, myosin-light-chain kinase, but not myosin; the catalytic subunit acts on all three substrates.
Purification and characterization of a multisubunit phosphatase from turkey gizzard smooth muscle. The effect of calmodulin binding to myosin light chain kinase on dephosphorylation.