ST. PAUL (AP) -- Lt. Gov. Tina Smith is resigning from the board overseeing the public-private partnership with Mayo Clinic before she heads to the U.S. Senate.

Smith has chaired the Destination Medical Center Board since its creation in 2013. The project is meant to help the famed hospital expand its Rochester base with a blend of private investment and taxpayer-funded infrastructure expansion.

But Smith was appointed earlier this month to replace Sen. Al Franken when he resigns, effective next week. Smith announced Thursday she'd step away from the Destination Medical Center Board.

Smith is set to be sworn into the U.S. Senate on Wednesday. Former Minneapolis Mayor and current board vice chair R.T. Rybak will replace Smith as chair in the interim.