Mo. Rev. Stat. § 393.720

Any commission established by joint contract under sections 393.700 to 393.770 shall constitute a body public and corporate of the state, exercising public powers for the benefit of its contracting members and in order to carry out the public purposes and the public functions of its contracting members. It shall have the duties, privileges, immunities, rights, liabilities and disabilities of its contracting members and as a public body politic and corporate, including the power to tax, but shall not have any additional taxing power separate from that of its members nor shall it have the benefit of the doctrine of sovereign immunity.