The final step of 40S ribosomal subunit maturation is controlled by a dual key lock. - Plassart L; Shayan R; Montellese C; Rinaldi D; Larburu N; Pichereaux C; Froment C; Lebaron S; O'Donohue MF; Kutay U; Marcoux J; Gleizes PE; et al. (ELife, 2021)