Methanogenic archaea encoding Pyrrolysine maintain ambiguous amber codon usage.

ABSTRACT: Natural genetic code expansion is a phenomenon wherein an additional amino acid is encoded by a stop codon. These nonstandard amino acids are beneficial as they facilitate novel biochemical reactions. However, code expansion leads to ambiguity at the recoded stop codon, which can either be read-through or terminated. Pyrrolysine (Pyl) is encoded by the amber codon (TAG/UAG) and is widespread in archaea, where it is required for methylamine-mediated methanogenesis, an environmentally important metabolism. Mechanisms to conditionally suppress the amber stop codon for Pyl installation during protein synthesis have not been identified. In the model methanogen, Methanosarcina acetivorans, we demonstrate that the UAG codon encodes dual meaning as stop and Pyl. Our data suggest that expres

SUBMITTER: Shalvarjian KE 

PROVIDER: S-EPMC12626013 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature