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122  structures 7200  species 0  interactions 9204  sequences 76  architectures

Family: HPPK (PF01288)

Summary: 7,8-dihydro-6-hydroxymethylpterin-pyrophosphokinase (HPPK)

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This is the Wikipedia entry entitled "2-amino-4-hydroxy-6-hydroxymethyldihydropteridine diphosphokinase". More...

2-amino-4-hydroxy-6-hydroxymethyldihydropteridine diphosphokinase Edit Wikipedia article

2-amino-4-hydroxy-6-hydroxymethyldihydropteridine diphosphokinase
EC number2.7.6.3
CAS number37278-23-2
IntEnzIntEnz view
ExPASyNiceZyme view
MetaCycmetabolic pathway
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO
7,8-dihydro-6-hydroxymethylpterin-pyrophosphokinase (HPPK)
PDB 1cbk EBI.jpg
7,8-dihydro-6-hydroxymethylpterin-pyrophosphokinase from haemophilus influenzae

In enzymology, a 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine diphosphokinase (EC is an enzyme that catalyzes the chemical reaction

ATP + 2-amino-4-hydroxy-6-hydroxymethyl-7,8-dihydropteridine AMP + (2-amino-4-hydroxy-7,8-dihydropteridin-6-yl)methyl diphosphate

Thus, the two substrates of this enzyme are ATP and 2-amino-4-hydroxy-6-hydroxymethyl-7,8-dihydropteridine, whereas its two products are AMP and (2-amino-4-hydroxy-7,8-dihydropteridin-6-yl)methyl diphosphate.

This enzyme belongs to the family of transferases, specifically those transferring two phosphorus-containing groups (diphosphotransferases). The systematic name of this enzyme class is ATP:2-amino-4-hydroxy-6-hydroxymethyl-7,8-dihydropteridine 6'-diphosphotransferase. Other names in common use include 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine pyrophosphokinase, H2-pteridine-CH2OH pyrophosphokinase, 7,8-dihydroxymethylpterin-pyrophosphokinase, HPPK, 7,8-dihydro-6-hydroxymethylpterin pyrophosphokinase, and hydroxymethyldihydropteridine pyrophosphokinase. This enzyme participates in folate biosynthesis.

This enzyme catalyses the first step in a three-step pathway leading to 7,8 dihydrofolate. Bacterial HPPK (gene folK or sulD) is a protein of 160 to 270 amino acids.[1] In the lower eukaryote Pneumocystis carinii, HPPK is the central domain of a multifunctional folate synthesis enzyme (gene fas).[2]

Structural studies

As of late 2007, 23 structures have been solved for this class of enzymes, with PDB accession codes 1DY3, 1EQ0, 1EQM, 1EX8, 1F9H, 1F9Y, 1G4C, 1HKA, 1HQ2, 1IM6, 1KBR, 1Q0N, 1RAO, 1RB0, 1RTZ, 1RU1, 1RU2, 1TMJ, 1TMM, 2BMB, 2CG8, 2F63, and 2F65.


  1. ^ Talarico TL, Ray PH, Dev IK, Merrill BM, Dallas WS (September 1992). "Cloning, sequence analysis, and overexpression of Escherichia coli folK, the gene coding for 7,8-dihydro-6-hydroxymethylpterin-pyrophosphokinase". J. Bacteriol. 174 (18): 5971–7. PMC 207135. PMID 1325970.
  2. ^ Volpe F, Dyer M, Scaife JG, Darby G, Stammers DK, Delves CJ (March 1992). "The multifunctional folic acid synthesis fas gene of Pneumocystis carinii appears to encode dihydropteroate synthase and hydroxymethyldihydropterin pyrophosphokinase". Gene. 112 (2): 213–8. doi:10.1016/0378-1119(92)90378-3. PMID 1313386.

Further reading

  • Richey DP, Brown GM (1969). "The biosynthesis of folic acid. IX. Purification and properties of the enzymes required for the formation of dihydropteroic acid". J. Biol. Chem. 244 (6): 1582–92. PMID 4304228.
  • Richey DP, Brown GM (1971). "Hydroxymethyldihydropteridine pyrophosphokinase and dihydropteroate synthetase from Escherichia coli". Methods Enzymol. 18B: 765–771. doi:10.1016/s0076-6879(71)18150-5.
  • Shiota T, Baugh CM, Jackson R, Dillard R (1969). "The enzymatic synthesis of hydroxymethyldihydropteridine pyrophosphate and dihydrofolate". Biochemistry. 8 (12): 5022–8. doi:10.1021/bi00840a052. PMID 4312465.
This article incorporates text from the public domain Pfam and InterPro: IPR000550

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7,8-dihydro-6-hydroxymethylpterin-pyrophosphokinase (HPPK) Provide feedback

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External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR000550

All organisms require reduced folate cofactors for the synthesis of a variety of metabolites. Most microorganisms must synthesise folate de novo because they lack the active transport system of higher vertebrate cells which allows these organisms to use dietary folates. Enzymes involved in folate biosynthesis are therefore targets for a variety of antimicrobial agents such as trimethoprim or sulphonamides. 7,8-dihydro-6-hydroxymethylpterin-pyrophosphokinase ( EC ) (HPPK) catalyses the attachment of pyrophosphate to 6-hydroxymethyl-7,8-dihydropterin to form 6-hydroxymethyl-7,8-dihydropteridine pyrophosphate. This is the first step in a three-step pathway leading to 7,8 dihydrofolate. Bacterial HPPK (gene folK or sulD) [ PUBMED:1325970 ] is a protein of 160 to 270 amino acids. In the lower eukaryote Pneumocystis carinii, HPPK is the central domain of a multifunctional folate synthesis enzyme (gene fas) [ PUBMED:1313386 ].

Gene Ontology

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Domain organisation

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We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database (reference proteomes) using the family HMM. We also generate alignments using four representative proteomes (RP) sets and the UniProtKB sequence database. More...

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Seed source: Prosite
Previous IDs: none
Type: Domain
Sequence Ontology: SO:0000417
Author: Finn RD , Bateman A
Number in seed: 854
Number in full: 9204
Average length of the domain: 129.40 aa
Average identity of full alignment: 37 %
Average coverage of the sequence by the domain: 53.26 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 61295632 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 25.7 25.7
Trusted cut-off 25.7 25.8
Noise cut-off 25.6 25.6
Model length: 111
Family (HMM) version: 23
Download: download the raw HMM for this family

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Archea Archea Eukaryota Eukaryota
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Viruses Viruses Unclassified Unclassified
Viroids Viroids Unclassified sequence Unclassified sequence


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For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the HPPK domain has been found. There are 122 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein sequence.

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