InterPro domain: IPR044634

Ribosome-associated J protein-Hsp70 chaperones promote nascent-polypeptide folding and normal translational fidelity. This entry includes J protein DnaJC2 from humans, Zuo1 from budding yeasts, and their homologues from other animals, fungi and plants [ 1 ]. DnaJC2 stimulates the ATPase activity of Hsp70 (Ssb1/2 in yeast) [ 2 ]. Zuo1 forms a stable heterodimeric complex termed ribosome-associated complex (RAC) with Ssz1 (an atypical Hsp70 family member, known as HspA14 in humans), this complex is then anchored to the ribosome via its Zuo1 subunit [ 3 ]. These three proteins (Ssb, Zuo1 and Ssz1) referred to as a chaperone triad lay a role together in folding of nascent polypeptides [ 4 ]. Moreover, Zuo1 has been shown to interact with the 40S and 60S ribosomal subunits in budding yeasts [ 4 ].

1. Dual interaction of the Hsp70 J-protein cochaperone Zuotin with the 40S and 60S ribosomal subunits. Nat. Struct. Mol. Biol. 23, 1003-1010
2. The Hsp70 Ssz1 modulates the function of the ribosome-associated J-protein Zuo1. Nat. Struct. Mol. Biol. 12, 497-504
3. Functional characterization of the atypical Hsp70 subunit of yeast ribosome-associated complex. J. Biol. Chem. 282, 33977-84