(1) The authority is a body corporate which may sue and be sued, plead and be impleaded, contract and be contracted with, and carry out all powers granted it. The authority shall be considered a governmental unit of this state for purposes of subpart 1 of part 21 (general real estate powers) of the natural resources and environmental protection act, Act No. 451 of the Public Acts of 1994, being section 324.2101 to 324.2102 of the Michigan Compiled Laws, and a public entity for purposes of Act No. 317 of the Public Acts of 1968, being section 15.321 to 15.330 of the Michigan Compiled Laws. The authority shall be considered a public agency for purposes of the urban cooperation act of 1967, Act No. 7 of the Public Acts of the Extra Session of 1967, being section 124.501 to 124.512 of the Michigan Compiled Laws.

  (2) A contract, deed of conveyance, and any other official paper of the authority shall be signed by the chairperson or vice-chairperson in the absence of the chairperson and attested by the secretary.

  (3) An authority shall be considered a public body and have those powers necessary to effectuate the purposes of this act. A grant of power to an authority shall not be construed as a limitation but rather as an extension of the power of the authority.