KnowraPyrrolysineLinked fromLinked fromThe 4 pages that link to Pyrrolysine, each with the reason it gives.All 4Broader topic 3Compared with 1Amino acidBroader topic: It expands the standard genetic code beyond the familiar 20 amino acids.Genetic codeBroader topic: It is a natural exception to the standard interpretation of UAG as a stop signal.Proteinogenic amino acidBroader topic: It is the rare twenty-second genetically encoded proteinogenic amino acid.SelenocysteineCompared with: Like selenocysteine, it expands the genetic code by recoding a stop codon.