Mo. Rev. Stat. § 475.339

Notwithstanding any other provision of law, a domiciliary guardian, committee, curator or conservator of a nonresident person, although a nonresident of this state or a corporation of another state or country, whether or not authorized to do business in this state, may act as such domiciliary guardian or conservator in this state under sections 475.335 and 475.336 and may be appointed and act as local guardian or conservator under section 475.030.