First contact

Mol. Cell (2019)

Ribosomes interact with various factors to enable the biogenesis of newly synthesized polypeptides, including the nascent polypeptide-associated complex (NAC) and the translocon Sec61. It’s generally thought that these ribosome-associated protein biogenesis factors don’t interact with nascent polypeptides until they exit the ribosome tunnel. However, a new study by Gamerdinger et al. challenges the concept. Through structural analysis of the reconstituted Caenorhabditis elegans NAC-60S ribosomal complex and site-specific crosslinking experiments, the authors revealed that the N terminus of the β subunit of NAC (N-βNAC) inserts deeply into the ribosomal tunnel to contact nascent peptide chains upon their synthesis and are then pushed out of the ribosome tunnel together. A NAC mutant with GFP fused to the N terminus of βNAC that has lost the ability to insert into the channel fails to rescue the embryonic lethal phenotype induced by loss of NAC, suggesting that the tunnel-sensing activity of N-βNAC is essential for its biological function. This study suggests a new type of co-translational regulatory event and lays a foundation for further investigation into the ribosome-associated protein networks.

Credit: Elsevier

Author information



Corresponding author

Correspondence to Yiyun Song.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Song, Y. First contact. Nat Chem Biol 15, 933 (2019).

Download citation


Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing