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MetaCyc Enzyme: 6-pyruvoyl tetrahydrobiopterin synthase

Gene: PTS Accession Number: G-10203 (MetaCyc)

Species: Homo sapiens

Subunit composition of 6-pyruvoyl tetrahydrobiopterin synthase = [(PTS)3]2
         6-pyruvoyl tetrahydrobiopterin synthase trimer = (PTS)3
                 6-pyruvoyl tetrahydrobiopterin synthase monomer = PTS

6-pyruvoyl tetrahydrobiopterin synthase, which catalyzes the conversion of 7,8-dihydroneopterin 3'-triphosphate to 6-pyruvoyl tetrahydropterin, was purified approximately 140,000-fold to apparent homogeneity from human liver [Takikawa86].

In addition, the PTS gene encoding the enzyme has been cloned from two cDNA libraries and expressed in Escherichia coli, and the recombinant proteins were purified [Ashida93, Burgisser94].

Cross-linking experiments and analysis by gel electrophoresis of the recombinant enzyme suggest that the native form is a homohexamer of 98 kDa composed of two trimeric subunits [Burgisser94]. This structure was confirmed when the crystal structure was solved at 2.3 Å [Nar94].

A transition metal binding site formed by three histidine residues in each subunit was shown to bind Zn2+ [Burgisser95].

Gene Citations: [Thony92]

Molecular Weight of Polypeptide: 16.386 kD (from nucleotide sequence), 17.0 kD (experimental) [Ashida93 ]

Molecular Weight of Multimer 6-pyruvoyl tetrahydrobiopterin synthase trimer: 50.0 kD (experimental) [Ashida93]

Molecular Weight of Multimer 6-pyruvoyl tetrahydrobiopterin synthase: 98.0 kD (experimental) [Burgisser94]

pI: 4.6 [Burgisser94]

Unification Links: ArrayExpress:Q03393, Mint:MINT-1419639, PhosphoSite:Q03393, PhylomeDB:Q03393, Pride:Q03393, Protein Model Portal:Q03393, SMR:Q03393, String:9606.ENSP00000280362, UniProt:Q03393

Relationship Links: Entrez-Nucleotide:PART-OF:M97655, InterPro:IN-FAMILY:IPR007115, InterPro:IN-FAMILY:IPR022469, InterPro:IN-FAMILY:IPR022470, Panther:IN-FAMILY:PTHR12589, PDB:Structure:3I2B, Pfam:IN-FAMILY:PF01242, Prosite:IN-FAMILY:PS00987, Prosite:IN-FAMILY:PS00988

Gene-Reaction Schematic

Gene-Reaction Schematic

Created 21-Sep-2007 by Caspi R, SRI International

Enzymatic reaction of: 6-pyruvoyl tetrahydrobiopterin synthase

Inferred from experiment

EC Number:

7,8-dihydroneopterin 3'-triphosphate → 6-pyruvoyl tetrahydropterin + PPPi + H+

The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the direction in which it was curated.

The reaction is physiologically favored in the direction shown.

In Pathways: tetrahydrobiopterin biosynthesis I, tetrahydrobiopterin biosynthesis II

Vmax of the purified recombinant protein was 0.84 μmol/min/mg protein [Ashida93]. Activity of the native purified enzyme was 8-fold lower.

Activators (Allosteric): Zn2+ [Burgisser95], Mg2+ [Takikawa86]Kinetic Parameters:
Substrate Km (μM) Citations
7,8-dihydroneopterin 3'-triphosphate 10.0 [Takikawa86]

pH(opt): 7.5 [Takikawa86]


Ashida93: Ashida A, Hatakeyama K, Kagamiyama H (1993). "cDNA cloning, expression in Escherichia coli and purification of human 6-pyruvoyl-tetrahydropterin synthase." Biochem Biophys Res Commun 195(3);1386-93. PMID: 8216273

Burgisser94: Burgisser DM, Thony B, Redweik U, Hunziker P, Heizmann CW, Blau N (1994). "Expression and characterization of recombinant human and rat liver 6-pyruvoyl tetrahydropterin synthase. Modified cysteine residues inhibit the enzyme activity." Eur J Biochem 219(1-2);497-502. PMID: 8307017

Burgisser95: Burgisser DM, Thony B, Redweik U, Hess D, Heizmann CW, Huber R, Nar H (1995). "6-Pyruvoyl tetrahydropterin synthase, an enzyme with a novel type of active site involving both zinc binding and an intersubunit catalytic triad motif; site-directed mutagenesis of the proposed active center, characterization of the metal binding site and modelling of substrate binding." J Mol Biol 253(2);358-69. PMID: 7563095

Nar94: Nar H, Huber R, Heizmann CW, Thony B, Burgisser D (1994). "Three-dimensional structure of 6-pyruvoyl tetrahydropterin synthase, an enzyme involved in tetrahydrobiopterin biosynthesis." EMBO J 13(6);1255-62. PMID: 8137809

Takikawa86: Takikawa S, Curtius HC, Redweik U, Leimbacher W, Ghisla S (1986). "Biosynthesis of tetrahydrobiopterin. Purification and characterization of 6-pyruvoyl-tetrahydropterin synthase from human liver." Eur J Biochem 161(2);295-302. PMID: 3536512

Thony92: Thony B, Leimbacher W, Burgisser D, Heizmann CW (1992). "Human 6-pyruvoyltetrahydropterin synthase: cDNA cloning and heterologous expression of the recombinant enzyme." Biochem Biophys Res Commun 189(3);1437-43. PMID: 1282802

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by Pathway Tools version 19.5 (software by SRI International) on Wed May 4, 2016, biocyc14.