TABLE 3.

Pathways for the essential amino acidsa

Amino acidVertebratesChordate C.i.InvertebratesUnicellularPlant A.t.Intracellular parasites
H.s.T.n.D.m.A.g.C.e.S.c.D.d.L.m.P.f.C.h.
Histidine++
Isoleucine++
Leucine++
Lysine++
Methionine++
Phenylalanine++
Threonine++
Tryptophan++
Valine++
  • a The synthesis capabilities of the following eukaryotic organisms are shown: H. sapiens (H.s.), T. nigroviridis (T.n.), C. intestinalis (C.i.), D. melanogaster (D.m.), A. gambiae (A.g.), C. elegans (C.e.), S. cerevisiae (S.c.), D. discoideum (D.d.), A. thaliana (A.t.), C. hominis (C.h.), L. major (L.m.), and P. falciparum (P.f.). A plus sign indicates that the genes for all of the enzymes of the biosynthetic pathway are present in the genome. A minus sign indicates that one or more of the genes encoding an enzyme in the pathway are missing in the genome.