Format

Send to

Choose Destination
Nat Struct Mol Biol. 2019 Jan;26(1):35-39. doi: 10.1038/s41594-018-0165-y. Epub 2018 Dec 17.

Ribosome-NatA architecture reveals that rRNA expansion segments coordinate N-terminal acetylation.

Author information

1
Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany.
2
Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany. becker@genzentrum.lmu.de.
3
Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany. beatrix@genzentrum.lmu.de.
4
Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany. beckmann@genzentrum.lmu.de.

Abstract

The majority of eukaryotic proteins are N-terminally α-acetylated by N-terminal acetyltransferases (NATs). Acetylation usually occurs co-translationally and defects have severe consequences. Nevertheless, it is unclear how these enzymes act in concert with the translating ribosome. Here, we report the structure of a native ribosome-NatA complex from Saccharomyces cerevisiae. NatA (comprising Naa10, Naa15 and Naa50) displays a unique mode of ribosome interaction by contacting eukaryotic-specific ribosomal RNA expansion segments in three out of four binding patches. Thereby, NatA is dynamically positioned directly underneath the ribosomal exit tunnel to facilitate modification of the emerging nascent peptide chain. Methionine amino peptidases, but not chaperones or signal recognition particle, would be able to bind concomitantly. This work assigns a function to the hitherto enigmatic ribosomal RNA expansion segments and provides mechanistic insights into co-translational protein maturation by N-terminal acetylation.

PMID:
30559462
DOI:
10.1038/s41594-018-0165-y

Supplemental Content

Full text links

Icon for Nature Publishing Group
Loading ...
Support Center