Component of the ribosome-associated complex (RAC), a heterodimeric chaperone complex involved in regulation of accurate translation termination and in folding or maintaining nascent polypeptides in a folding-competent state. RAC stimulates the ATPase activity of the ribosome-associated pool of Hsp70-type chaperones SSB1/SSB2 that bind to the nascent polypeptide chain. ZUO1 can act as a J-protein for SSB1/SSB2 only when associated with SSZ1. RAC is a heterodimer of the Hsp70/DnaK-type chaperone SSZ1 and the Hsp40/DnaJ-type chaperone ZUO1. RAC associates with ribosomes via ZUO1. Present with 86400 molecules/cell in log phase SD medium.