are actin and myosin proteins
The main contractile system of all muscular tissue are based on the interactions of two proteins Actin and Myosin. The system of these proteins some times called actin-myosin contractile system. Actin is one of the most condensed forms of protein, which is globular and is a monomeric subunit of microfilament. The thin filaments in actin constitute a major part of it.