Myosin is composed of 2 heavy chains of about 200 kD each and 4 light chains of about 20,000 daltons each. The light chains are of 2 distinct types: the phosphorylatable, regulatory, or MLC2 type, and the nonphosphorylatable, alkali, or MLC1 and MLC3 types. Skeletal Myosin (fast), also known as MYL1, mapped to the region 2q32.1-qter.
