Abstract The most common cyanotoxin microcystin is a cyclic heptapeptide produced by non-ribosomal peptide-polyketide synthetases and tailoring enzymes. The tailoring enzyme McyI. a 2-hydroxyacid dehydrogenase. converts (3-methyl)malate into (3-methyl)oxaloacetate to produce the non-proteinogenic amino acid (3-methyl)aspartate. https://darthomes.shop/product-category/gift-cards/