Accepted name: aromatic 2-oxoacid reductase
Reaction: (1) (R)-3-(phenyl)lactate + NAD+ = 3-phenylpyruvate + NADH + H+
(2) (R)-3-(4-hydroxyphenyl)lactate + NAD+ = 3-(4-hydroxyphenyl)pyruvate + NADH + H+
(3) (R)-(indol-3-yl)lactate + NAD+ = (indol-3-yl)pyruvate + NADH + H+
Glossary: 3-phenylpyruvate = 2-oxo-3-phenylpropanoate
Other name(s): (R)-aromatic lactate dehydrogenase; (R)-4-hydroxyphenyllactate dehydrogenase; indolelactate:NAD+ oxidoreductase; indolelactate dehydrogenase; fldH (gene name); (indol-3-yl)lactate:NAD+ oxidoreductase
Systematic name: aromatic 2-oxoacid:NAD+ oxidoreductase
Comments: The enzymes from anaerobic bacteria such as Clostridium sporogenes participate in the fermentation pathways of L-phenylalanine, L-tyrosine and L-tryptophan. The enzyme from the yeast Candida maltosa has similar activity, but, unlike the bacterial enzyme, requires Mn2+ and can also use NADPH with lower activity.
1.  Jean, M. and DeMoss, R.D. Indolelactate dehydrogenase from Clostridium sporogenes. Can. J. Microbiol. 14 (1968) 429–435. [PMID: 4384683]
2.  Giesel, H. and Simon, H. On the occurrence of enoate reductase and 2-oxo-carboxylate reductase in clostridia and some observations on the amino acid fermentation by Peptostreptococcus anaerobius. Arch. Microbiol. 135 (1983) 51–57. [PMID: 6354130]
3.  Bode, R., Lippoldt, A. and Birnbaum, D. Purification and properties of D-aromatic lactate dehydrogenase an enzyme involved in the catabolism of the aromatic amino acids of Candida maltosa. Biochem. Physiol. Pflanzen 181 (1986) 189–198.
4.  Dickert, S., Pierik, A.J., Linder, D. and Buckel, W. The involvement of coenzyme A esters in the dehydration of (R)-phenyllactate to (E)-cinnamate by Clostridium sporogenes. Eur. J. Biochem. 267 (2000) 3874–3884. [PMID: 10849007]
5.  Dodd, D., Spitzer, M.H., Van Treuren, W., Merrill, B.D., Hryckowian, A.J., Higginbottom, S.K., Le, A., Cowan, T.M., Nolan, G.P., Fischbach, M.A. and Sonnenburg, J.L. A gut bacterial pathway metabolizes aromatic amino acids into nine circulating metabolites. Nature 551 (2017) 648–652. [PMID: 29168502]
[EC created 1972 (EC created 2000, incorporated 2018), modified 2018]
Accepted name: phenylpyruvate C3-methyltransferase
Reaction: S-adenosyl-L-methionine + 3-phenylpyruvate = S-adenosyl-L-homocysteine + (3S)-2-oxo-3-phenylbutanoate
Glossary: 3-phenylpyruvate = 2-oxo-3-phenylpropanoate
(3S)-2-oxo-3-phenylbutanoate = (3S)-β-methyl-phenylpyruvate
Other name(s): phenylpyruvate Cβ-methyltransferase; phenylpyruvate methyltransferase; mppJ (gene name)
Systematic name: S-adenosyl-L-methionine:2-oxo-3-phenylpropanoate C3-methyltransferase
Comments: The enzyme from the bacterium Streptomyces hygroscopicus NRRL3085 is involved in synthesis of the nonproteinogenic amino acid (2S,3S)-β-methyl-phenylalanine, a building block of the antibiotic mannopeptimycin.
1.  Huang, Y.T., Lyu, S.Y., Chuang, P.H., Hsu, N.S., Li, Y.S., Chan, H.C., Huang, C.J., Liu, Y.C., Wu, C.J., Yang, W.B. and Li, T.L. In vitro characterization of enzymes involved in the synthesis of nonproteinogenic residue (2S,3S)-β-methylphenylalanine in glycopeptide antibiotic mannopeptimycin. ChemBioChem 10 (2009) 2480–2487. [PMID: 19731276]
[EC created 2013]