This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
|Superclasses:||Degradation/Utilization/Assimilation → Amino Acids Degradation → Tyrosine Degradation|
Some taxa known to possess this pathway include : Saccharomyces cerevisiae
Expected Taxonomic Range: Fungi
While Saccharomyces cerevisiae can utilize only a limited range of carbon sources [Barnett92] it can obtain its nitrogen from many different sources, including most amino acids [Large68]. The most common mechanism for retreiving the nitrogen from amino acids is transamination, using 2-oxoglutarate or other 2-oxo acids as amino acceptors. This process leaves the carbon skeleton of the amino acid intact, in the form of a 2-oxo acid. In a few cases the resulting 2-oxo acid can be directly fed into central metabolism (such as the case of L-alanine and its derived 2-keto acid, pyruvate). In most cases, though, the 2-oxo acids resulting from transamination are not intermediates of central metabolism, and are excreted from the cells after some transformation.
An important and common pathway for catabolism of amino acids by yeast is the Ehrlich pathway [Ehrlich07]. In this pathway, following transamination of an amino acid into the corresponding 2-oxo acid, the 2-oxo acid is decarboxylated to an aldehyde. Depending on the redox status of the cells [Vuralhan03], the aldehydes can then be either reduced (by alcohol dehydrogenases) to alcohols, which are called collectively "fusel alcohols", or oxidized by aldehyde dehydrogenases to organic acids ("fusel acids") [Vuralhan05].
This pathway illustrates the Ehrlich pathway for L-tyrosine. The first reaction of this pathway can be catalyzed by both the constitutive aromatic amino acid aminotransferase I (ARO8) and the inducible aromatic amino acid aminotransferase II (ARO9) [Kradolfer82].
In vitro studies demonstrated that Aro9p is active with 2-oxo-3-phenylpropanoate, pyruvate, or 4-hydroxyphenylpyruvate, but not 2-oxoglutarate as the amino acceptor, while Aro8p is active with 2-oxo-3-phenylpropanoate, pyruvate, or 2-oxoglutarate [Kradolfer82].
Iraqui98: Iraqui I, Vissers S, Cartiaux M, Urrestarazu A (1998). "Characterisation of Saccharomyces cerevisiae ARO8 and ARO9 genes encoding aromatic aminotransferases I and II reveals a new aminotransferase subfamily." Mol Gen Genet 257(2);238-48. PMID: 9491083
Kradolfer82: Kradolfer P, Niederberger P, Hutter R (1982). "Tryptophan degradation in Saccharomyces cerevisiae: characterization of two aromatic aminotransferases." Arch Microbiol 133(3);242-8. PMID: 6763508
Urrestarazu98: Urrestarazu A, Vissers S, Iraqui I, Grenson M (1998). "Phenylalanine- and tyrosine-auxotrophic mutants of Saccharomyces cerevisiae impaired in transamination." Mol Gen Genet 257(2);230-7. PMID: 9491082
Vuralhan03: Vuralhan Z, Morais MA, Tai SL, Piper MD, Pronk JT (2003). "Identification and characterization of phenylpyruvate decarboxylase genes in Saccharomyces cerevisiae." Appl Environ Microbiol 69(8);4534-41. PMID: 12902239
Vuralhan05: Vuralhan Z, Luttik MA, Tai SL, Boer VM, Morais MA, Schipper D, Almering MJ, Kotter P, Dickinson JR, Daran JM, Pronk JT (2005). "Physiological characterization of the ARO10-dependent, broad-substrate-specificity 2-oxo acid decarboxylase activity of Saccharomyces cerevisiae." Appl Environ Microbiol 71(6);3276-84. PMID: 15933030
Boer03: Boer VM, de Winde JH, Pronk JT, Piper MD (2003). "The genome-wide transcriptional responses of Saccharomyces cerevisiae grown on glucose in aerobic chemostat cultures limited for carbon, nitrogen, phosphorus, or sulfur." J Biol Chem 278(5);3265-74. PMID: 12414795
Cheraiti08: Cheraiti N, Sauvage FX, Salmon JM (2008). "Acetaldehyde addition throughout the growth phase alleviates the phenotypic effect of zinc deficiency in Saccharomyces cerevisiae." Appl Microbiol Biotechnol 77(5);1093-109. PMID: 17938904
Collier72: Collier RH, Kohlhaw G (1972). "Nonidentity of the aspartate and the aromatic aminotransferase components of transaminase A in Escherichia coli." J Bacteriol 1972;112(1);365-71. PMID: 4404056
DeEknamkul87: De-Eknamkul W, Ellis BE (1987). "Purification and characterization of tyrosine aminotransferase activities from Anchusa officinalis cell cultures." Arch Biochem Biophys 257(2);430-8. PMID: 2889425
Dietrich91: Dietrich JB, Lorber B, Kern D (1991). "Expression of mammalian tyrosine aminotransferase in Saccharomyces cerevisiae and Escherichia coli. Purification to homogeneity and characterization of the enzyme overproduced in the bacteria." Eur J Biochem 201(2);399-407. PMID: 1682148
Fauchon02: Fauchon M, Lagniel G, Aude JC, Lombardia L, Soularue P, Petat C, Marguerie G, Sentenac A, Werner M, Labarre J (2002). "Sulfur sparing in the yeast proteome in response to sulfur demand." Mol Cell 9(4);713-23. PMID: 11983164
Feldmann94: Feldmann H, Aigle M, Aljinovic G, Andre B, Baclet MC, Barthe C, Baur A, Becam AM, Biteau N, Boles E (1994). "Complete DNA sequence of yeast chromosome II." EMBO J 13(24);5795-809. PMID: 7813418
Flikweert96: Flikweert MT, Van Der Zanden L, Janssen WM, Steensma HY, Van Dijken JP, Pronk JT (1996). "Pyruvate decarboxylase: an indispensable enzyme for growth of Saccharomyces cerevisiae on glucose." Yeast 12(3);247-57. PMID: 8904337
Ganzhorn87: Ganzhorn AJ, Green DW, Hershey AD, Gould RM, Plapp BV (1987). "Kinetic characterization of yeast alcohol dehydrogenases. Amino acid residue 294 and substrate specificity." J Biol Chem 262(8);3754-61. PMID: 3546317
Gu98: Gu W, Song J, Bonner CA, Xie G, Jensen RA (1998). "PhhC is an essential aminotransferase for aromatic amino acid catabolism in Pseudomonas aeruginosa." Microbiology 144 ( Pt 11);3127-34. PMID: 9846749
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