Mo. Rev. Stat. § 295.040

Each member of said board shall, before entering upon the duties of his office, take and subscribe an oath to support the Constitution of the United States and this state and to demean himself faithfully in his office. The main office of the state board of mediation shall be in Jefferson City, but the board may hold meetings at any time or any place in the state whenever the same shall become necessary, and three members of the board shall constitute a quorum for the transaction of business.