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6-pyruvoyl tetrahydrobiopterin synthase; PTP synthase (PTPS, PTS)
Function:
- role in the biosynthesis of tetrahydrobiopterin
- catalyzes transformation of 7,8-dihydroneopterin triphosphate into 6-pyruvoyl tetrahydropterin
- cofactor biosynthesis; tetrahydrobiopterin biosynthesis
- tetrahydrobiopterin from 2-amino-4-hydroxy-6-(erythro-1,2,3- trihydroxypropyl)-dihydropteridine triphosphate: step 1/3
- phosphorylation of Ser-19 is required for maximal enzyme activity
7,8-dihydroneopterin 3'-triphosphate
6-pyruvoyl-5,6,7,8-tetrahydropterin + triphosphate
Cofactor: binds 1 Zn+2 per subunit (putative)
Kinetic parameters:
- KM=8.1 uM for 7,8-dihydroneopterin triphosphate
- Vmax=120 nmol/min/mg enzyme
Structure:
- homohexamer formed of two homotrimers in a head to head fashion
- belongs to the PTPS family
- the active site is at the interface between 2 subunits
- the proton acceptor Cys is on one subunit, & the charge relay system is on the other subunit
Pathology:
- defects in PTS are a cause of hyperphenylalaninemia
General
phosphoprotein
synthase
Properties
SIZE: entity length = 145 aa
MW = 16 kD
MOTIF: Ser phosphorylation site {S19}
Zn+2-binding site
SITE: 24-24
cysteine residue {C43}
Zn+2-binding site
SITE: 49-49
Zn+2-binding site
SITE: 51-51
histidine residue {H90}
glutamate residue {E134}
Database Correlations
OMIM 261640
UniProt Q03393
Pfam PF01242
Entrez Gene 5805
Kegg hsa:5805
ENZYME 4.2.3.12
References
- UniProt :accession Q03393
- BIOMDB;
Db of mutations causing tetrahydrobiopterin deficiencies
http://www.bh4.org/biodef1.html
- GeneReviews
https://www.genecards.org/cgi-bin/carddisp.pl?gene=PTS