Download MendeleyDual interaction of the Hsp70 J-protein cochaperone Zuotin with the 40S and 60S ribosomal subunits.
Lee, K., Sharma, R., Shrestha, O.K., Bingman, C.A., Craig, E.A.(2016) Nat Struct Mol Biol 23: 1003-1010
- PubMed: 27669034
- DOI: https://doi.org/10.1038/nsmb.3299
- Primary Citation of Related Structures:
5DJE - PubMed Abstract:
Ribosome-associated J protein-Hsp70 chaperones promote nascent-polypeptide folding and normal translational fidelity. The J protein Zuo1 is known to span the ribosomal subunits, but understanding of its function is limited. Here we present new structural and cross-linking data allowing more precise positioning of Saccharomyces cerevisiae Zuo1 near the 60S polypeptide-exit site and suggesting interactions of Zuo1 with the ribosomal protein eL31 and 25S rRNA helix 24. The junction between the 60S-interacting and subunit-spanning helices is a hinge that positions Zuo1 on the 40S yet accommodates subunit rotation. Interaction between the Zuo1 C terminus and 40S occurs via 18S rRNA expansion segment 12 (ES12) of helix 44, which originates at the decoding site. Deletions in either ES12 or the Zuo1 C terminus alter readthrough of stop codons and -1 frameshifting. Our study offers insight into how this cotranslational chaperone system may monitor decoding-site activity and nascent-polypeptide transit, thereby coordinating protein translation and folding.
Organizational Affiliation:
Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA.
