|Gene:||folK||Accession Numbers: EG11374 (MetaCyc), b0142, ECK0141|
Species: Escherichia coli K-12 substr. MG1655
6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK) catalyzes a reaction in the folate biosynthesis pathway, the transfer of pyrophosphate from ATP to 6-hydroxymethyl-7,8-dihydropterin [Talarico92]. HPPK is essential in microorganisms, and the enzyme is not present in mammals; it is therefore a target for the development of antimicrobial drugs.
Various crystal and solution structures of HPPK have been solved and have elucidated the reaction mechanism and kinetics. The protein undergoes conformational changes during the catalytic cycle. [Xiao99, Shi99, Stammers99, Blaszczyk00, Shi01, Yan01, Xiao01, Blaszczyk03, Blaszczyk04, Blaszczyk04a, Garcon04, Yang05b, Li05c, Li06c, Lescop09, Su09]
The enzyme binds ATP first, which then enables faster binding of 6-hydroxymethyl-7,8-dihydropterin (HMDP) [Bermingham00]. Mg2+ is important for binding of both ATP and HMDP [Li02a]. The roles in substrate binding and catalysis of several amino acid residues in the flexible loop 3 have been investigated by site-directed mutagenesis [Li03c, Blaszczyk04, Li05c].
|Map Position: [157,253 <- 157,732]|
Molecular Weight of Polypeptide: 18.079 kD (from nucleotide sequence), 23.0 kD (experimental) [Talarico92 ]
Unification Links: ASAP:ABE-0000491 , CGSC:29572 , EchoBASE:EB1348 , EcoGene:EG11374 , EcoliWiki:b0142 , EcoO157Cyc:FOLK-MONOMER , ModBase:P26281 , OU-Microarray:b0142 , PortEco:folK , PR:PRO_000022680 , Protein Model Portal:P26281 , RefSeq:NP_414684 , RegulonDB:EG11374 , SMR:P26281 , String:511145.b0142 , UniProt:P26281
Relationship Links: InterPro:IN-FAMILY:IPR000550 , PDB:Structure:1DY3 , PDB:Structure:1EQ0 , PDB:Structure:1EQM , PDB:Structure:1EX8 , PDB:Structure:1F9H , PDB:Structure:1G4C , PDB:Structure:1HKA , PDB:Structure:1HQ2 , PDB:Structure:1IM6 , PDB:Structure:1KBR , PDB:Structure:1Q0N , PDB:Structure:1RAO , PDB:Structure:1RB0 , PDB:Structure:1RTZ , PDB:Structure:1RU1 , PDB:Structure:1RU2 , PDB:Structure:1TMJ , PDB:Structure:1TMM , PDB:Structure:2F63 , PDB:Structure:2F65 , PDB:Structure:3HCX , PDB:Structure:3HD1 , PDB:Structure:3HD2 , PDB:Structure:3HSD , PDB:Structure:3HSG , PDB:Structure:3HSJ , PDB:Structure:3HSZ , PDB:Structure:3HT0 , PDB:Structure:3ILI , PDB:Structure:3ILJ , PDB:Structure:3ILL , PDB:Structure:3ILO , PDB:Structure:3IP0 , PDB:Structure:3KUE , PDB:Structure:3KUG , PDB:Structure:3KUH , PDB:Structure:3UD5 , PDB:Structure:3UDE , PDB:Structure:3UDV , PDB:Structure:4F7V , Pfam:IN-FAMILY:PF01288 , Prosite:IN-FAMILY:PS00794
|Biological Process:||GO:0009396 - folic acid-containing compound biosynthetic process
GO:0016310 - phosphorylation [UniProtGOA11]
GO:0046654 - tetrahydrofolate biosynthetic process [UniProtGOA12]
GO:0046656 - folic acid biosynthetic process [UniProtGOA11]
|Molecular Function:||GO:0000287 - magnesium ion binding
GO:0003848 - 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine diphosphokinase activity [GOA01a, GOA01, Talarico91, Talarico92]
GO:0000166 - nucleotide binding [UniProtGOA11]
GO:0005524 - ATP binding [UniProtGOA11]
GO:0016301 - kinase activity [UniProtGOA11]
GO:0016740 - transferase activity [UniProtGOA11]
|Cellular Component:||GO:0005829 - cytosol [DiazMejia09]|
|MultiFun Terms:||metabolism → biosynthesis of building blocks → cofactors, small molecule carriers → folic acid|
Enzymatic reaction of: 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase
Synonyms: 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine pyrophosphokinase, PPPK, 7,8-dihydro-6-hydroxymethylpterin pyrophosphokinase, HPPK, hydroxymethyldihydropterin pyrophosphokinase, ATP:2-amino-4-hydroxy-6-hydroxymethyl-7,8-dihydropteridine 6'-pyrophosphotransferase
EC Number: 184.108.40.206
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction of enzyme catalysis.
The reaction is physiologically favored in the direction shown.
In Pathways: superpathway of tetrahydrofolate biosynthesis and salvage , superpathway of chorismate metabolism , superpathway of tetrahydrofolate biosynthesis , 6-hydroxymethyl-dihydropterin diphosphate biosynthesis I
The enzyme was first purified from E. coli B [Richey69].
The enzyme is highly specific for ATP [Bermingham00].
|Chain||2 -> 159|
10/20/97 Gene b0142 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG11374; confirmed by SwissProt match.
Ballantine94: Ballantine SP, Volpe F, Delves CJ (1994). "The hydroxymethyldihydropterin pyrophosphokinase domain of the multifunctional folic acid synthesis Fas protein of Pneumocystis carinii expressed as an independent enzyme in Escherichia coli: refolding and characterization of the recombinant enzyme." Protein Expr Purif 5(4);371-8. PMID: 7950384
Bermingham00: Bermingham A, Bottomley JR, Primrose WU, Derrick JP (2000). "Equilibrium and kinetic studies of substrate binding to 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase from Escherichia coli." J Biol Chem 275(24);17962-7. PMID: 10751386
Blaszczyk00: Blaszczyk J, Shi G, Yan H, Ji X (2000). "Catalytic center assembly of HPPK as revealed by the crystal structure of a ternary complex at 1.25 A resolution." Structure 8(10);1049-58. PMID: 11080626
Blaszczyk03: Blaszczyk J, Li Y, Shi G, Yan H, Ji X (2003). "Dynamic roles of arginine residues 82 and 92 of Escherichia coli 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase: crystallographic studies." Biochemistry 42(6);1573-80. PMID: 12578370
Blaszczyk04: Blaszczyk J, Li Y, Wu Y, Shi G, Ji X, Yan H (2004). "Essential roles of a dynamic loop in the catalysis of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase." Biochemistry 43(6);1469-77. PMID: 14769023
Blaszczyk04a: Blaszczyk J, Shi G, Li Y, Yan H, Ji X (2004). "Reaction trajectory of pyrophosphoryl transfer catalyzed by 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase." Structure (Camb) 12(3);467-75. PMID: 15016362
DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114
Garcon04: Garcon A, Bermingham A, Lian LY, Derrick JP (2004). "Kinetic and structural characterization of a product complex of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase from Escherichia coli." Biochem J 380(Pt 3);867-73. PMID: 15018613
Lescop09: Lescop E, Lu Z, Liu Q, Xu H, Li G, Xia B, Yan H, Jin C (2009). "Dynamics of the conformational transitions in the assembling of the Michaelis complex of a bisubstrate enzyme: a (15)N relaxation study of Escherichia coli 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase." Biochemistry 48(2);302-12. PMID: 19108643
Li02a: Li Y, Gong Y, Shi G, Blaszczyk J, Ji X, Yan H (2002). "Chemical transformation is not rate-limiting in the reaction catalyzed by Escherichia coli 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase." Biochemistry 41(27);8777-83. PMID: 12093297
Li03c: Li Y, Wu Y, Blaszczyk J, Ji X, Yan H (2003). "Catalytic roles of arginine residues 82 and 92 of Escherichia coli 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase: site-directed mutagenesis and biochemical studies." Biochemistry 42(6);1581-8. PMID: 12578371
Li05c: Li Y, Blaszczyk J, Wu Y, Shi G, Ji X, Yan H (2005). "Is the critical role of loop 3 of Escherichia coli 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase in catalysis due to loop-3 residues arginine-84 and tryptophan-89? Site-directed mutagenesis, biochemical, and crystallographic studies." Biochemistry 44(24);8590-9. PMID: 15952765
Li06c: Li G, Felczak K, Shi G, Yan H (2006). "Mechanism of the conformational transitions in 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase as revealed by NMR spectroscopy." Biochemistry 45(41);12573-81. PMID: 17029412
Richey69: 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 1969;244(6);1582-92. PMID: 4304228
Shi00: Shi G, Gong Y, Savchenko A, Zeikus JG, Xiao B, Ji X, Yan H (2000). "Dissecting the nucleotide binding properties of Escherichia coli 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase with fluorescent 3'(2)'-o-anthraniloyladenosine 5'-triphosphate." Biochim Biophys Acta 1478(2);289-99. PMID: 10825540
Shi01: Shi G, Blaszczyk J, Ji X, Yan H (2001). "Bisubstrate analogue inhibitors of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase: synthesis and biochemical and crystallographic studies." J Med Chem 44(9);1364-71. PMID: 11311059
Shi99: Shi G, Gao J, Yan H (1999). "1H, 13C and 15N resonance assignments of Escherichia coli 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase and its complex with MgAMPPCP." J Biomol NMR 14(2);189-90. PMID: 10427747
Stammers99: Stammers DK, Achari A, Somers DO, Bryant PK, Rosemond J, Scott DL, Champness JN (1999). "2.0 A X-ray structure of the ternary complex of 7,8-dihydro-6-hydroxymethylpterinpyrophosphokinase from Escherichia coli with ATP and a substrate analogue." FEBS Lett 456(1);49-53. PMID: 10452528
Talarico91: Talarico TL, Dev IK, Dallas WS, Ferone R, Ray PH (1991). "Purification and partial characterization of 7,8-dihydro-6-hydroxymethylpterin-pyrophosphokinase and 7,8-dihydropteroate synthase from Escherichia coli MC4100." J Bacteriol 173(21);7029-32. PMID: 1657875
Talarico92: Talarico TL, Ray PH, Dev IK, Merrill BM, Dallas WS (1992). "Cloning, sequence analysis, and overexpression of Escherichia coli folK, the gene coding for 7,8-dihydro-6-hydroxymethylpterin-pyrophosphokinase." J Bacteriol 1992;174(18);5971-7. PMID: 1325970
Xiao01: Xiao B, Shi G, Gao J, Blaszczyk J, Liu Q, Ji X, Yan H (2001). "Unusual conformational changes in 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase as revealed by X-ray crystallography and NMR." J Biol Chem 276(43);40274-81. PMID: 11546767
Xiao99: Xiao B, Shi G, Chen X, Yan H, Ji X (1999). "Crystal structure of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase, a potential target for the development of novel antimicrobial agents." Structure 7(5);489-96. PMID: 10378268
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