Nascent Polypeptide-associated Complex (NAC) was identified in eukaryotes as the first cytosolic factor which contacts the nascent polypeptide chain emerging from the ribosome. NAC is present as a homodimer in Archaea and as a highly conserved heterodimer in eukaryotes. Mutations in NAC cause severe embryonically lethal phenotypes in mice, D. melanogaster and C. elegans. In the yeast Saccharomyces cerevisiae NAC is quantitatively associated with ribosomes. Here we show that NAC contacts several ribosomal proteins. The N-terminus of betaNAC, however, specifically contacts near the tunnel exit the ribosomal protein Rpl31, which is unique to Eukaryotes and Archaea. Moreover, the first 23 amino acids of betaNAC are sufficient to direct an otherwise non-associated protein to the ribosome. In contrast, alphaNAC (Egd2p) contacts Rpl17, the direct neighbour of Rpl31 at the ribosomal tunnel exit site. Rpl31 was recently also identified as a contact site for the SRP receptor and the ribosome associated complex (RAC). Furthermore, in E. coli peptide deformylase (PDF) interacts with the corresponding surface area on the eubacterial ribosome. In addition to the previously identified universal adapter site represented by Rpl25/35, we therefore refer to Rpl31/Rpl17 as a novel universal docking site for ribosome-associated factors on the eukaryotic ribosome.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Annotation Extension||Reference|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Assay||Construct||Conditions||Strain Background||Reference|