title: Reassigning stop codons via translation termination: How a few eukaryotes broke the dogma.
abstract: The genetic code determines how amino acids are encoded within mRNA. It is universal among the vast majority of organisms, although several exceptions are known. Variant genetic codes are found in ciliates, mitochondria, and numerous other organisms. All revealed genetic codes (standard and variant) have at least one codon encoding a translation stop signal. However, recently two new genetic codes with a reassignment of all three stop codons were revealed in studies examining the protozoa transcriptomes. Here, we discuss this finding and the recent studies of variant genetic codes in eukaryotes. We consider the possible molecular mechanisms allowing the use of certain codons as sense and stop signals simultaneously. The results obtained by studying these amazing organisms represent a new and exciting insight into the mechanism of stop codon decoding in eukaryotes. Also see the video abstract here.
authors.affiliation: Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, Moscow, Russia.
authors.forename: Elena
authors.initials: E
authors.lastname: Alkalaeva
authors.affiliation: Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, Moscow, Russia.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Mikhailova
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D018388:Codon, Terminator; D056890:Eukaryota / Q000235:genetics; D019143:Evolution, Molecular; D006801:Humans; D010443:Peptide Chain Termination, Translational; D010454:Peptide Termination Factors / Q000502:physiology
chemical_list: D020413:3' Untranslated Regions; D018388:Codon, Terminator; D010454:Peptide Termination Factors
keywords: PABP; genetic code; reassignment; stop codon; translation termination