The path of lysine to pyrrolysine.

The path of lysine to pyrrolysine. Curr Opin Chem Biol. 2013 Jul 12; Authors: Krzycki JA Abstract Pyrrolysine is the 22nd genetically encoded amino acid. For many years, its biosynthesis has been primarily a matter for conjecture. Recently, a pathway for the synthesis of pyrrolysine from two molecules of lysine was outlined in which a radical SAM enzyme acts as a lysine mutase to generate a methylated ornithine from lysine, which is then ligated to form an amide with the ɛ-amine of a second lysine. Oxidation of the isopeptide gives rise to pyrrolysine. Mechanisms have been proposed for both the mutase and the ligase, and structures now exist for each, setting the stage for a more detailed understanding of how pyrrolysine is synthesized and functions in bacteria and archaea. PMID: 23856058 [PubMed - as supplied by publisher]
Source: Current Opinion in Chemical Biology - Category: Biochemistry Authors: Tags: Curr Opin Chem Biol Source Type: research