(

a) All money received by the board from whatever source derived shall be deposited in the State Treasury to the credit of the Public Buildings Construction Fund, which is hereby created and appropriated for the purposes hereinafter provided. There shall be maintained, within the fund, subfunds, accounts, and subaccounts, as necessary, for the operation of the board and the performance of its obligations as provided in the applicable resolution, indenture, or other agreement. (

b) There shall be deposited in the fund to the credit of the respective series of certificates or revenue bonds authorized under the provisions of this part, the proceeds from the sale thereof. The money so deposited shall be expended, for the purposes authorized by this part, or as provided in the applicable resolution, indenture, or other agreement, for the cost of public buildings, and all additional amounts authorized by the board in accordance with

Section 15849.6. (

c) All revenues, rentals, or receipts received by the board, except those deposited in the Expense Account established by

Section 15845.2, shall be set aside at regular intervals as provided in the applicable resolution, indenture, or other agreement for each series of certificates or revenue bonds for the payment of interest and principal upon those certificates or revenue bonds as they fall due, or may be applied to an early redemption of those certificates or revenue bonds. Any revenues, rentals, or receipts remaining after the scheduled payment of principal and interest on a series in a year may be applied to any lawful purpose as determined by the board to the extent permitted in the applicable resolution, indenture, or other agreement for that series.