Notwithstanding subdivisions (1), (2), (3), (4) and (5) of this subsection, a corporation, whether or not a domestic corporation, may elect by a provision of its original articles of incorporation or any amendment thereto to be governed by this section; provided that any such amendment to the articles of incorporation shall not apply to restrict a business combination between the corporation and an interested shareholder of the corporation or any of its affiliates or associates if the interested shareholder became such prior to the effective date of the amendment.
§ 351.459, RSMo