The governor shall appoint three commissioners, each of whom shall be a member of the bar of this state, in good standing, who shall constitute and be known as the commission on uniform state laws, and upon the death, resignation, or refusal to serve of any of the commissioners so appointed, the governor shall make an appointment to fill the vacancy so caused, such new appointment to be for the unexpired balance of the term of the original appointee.
Iowa Code § 5.1