The N-end rule at atomic resolution

The N-end rule relates the in vivo half-life of a protein to the identity of its N-terminal residue. The N-end rule pathway, ubiquitin-dependent in eukaryotes, is also present in prokaryotes, which lack the ubiquitin system. An illuminating new study presents the crystal structure of a bacterial N-end rule recognition component in complex with a peptide containing a cognate degradation signal.