sulfur amino acid metabolic process L-methionine metabolic process https://github.com/geneontology/go-ontology/issues/31318 methionine and threonine metabolism methionine metabolism GO:0006555 methionine and threonine metabolic process The chemical reactions and pathways involving L-methionine (2-amino-4-(methylthio)butanoic acid), a sulfur-containing, essential amino acid found in peptide linkage in proteins. L-amino acid metabolic process proteinogenic amino acid metabolic process