Accepted name: 2-dehydropantolactone reductase
Reaction: (R)-pantolactone + NADP+ = 2-dehydropantolactone + NADPH + H+
Other name(s): 2-oxopantoyl lactone reductase; 2-ketopantoyl lactone reductase; ketopantoyl lactone reductase; 2-dehydropantoyl-lactone reductase
Systematic name: (R)-pantolactone:NADP+ oxidoreductase
Comments: The enzyme participates in an alternative pathway for biosynthesis of (R)-pantothenate (vitamin B5). This entry covers enzymes whose stereo specificity for NADP+ is not known. cf. EC 2-dehydropantolactone reductase (Re-specific) and EC, 2-dehydropantolactone reductase (Si-specific).
1.  Hata, H., Shimizu, S., Hattori, S. and Yamada, H. Ketopantoyl-lactone reductase from Candida parapsilosis: purification and characterization as a conjugated polyketone reductase. Biochim. Biophys. Acta 990 (1989) 175–181. [PMID: 2644973]
[EC created 2013]
Accepted name: pantothenate kinase
Reaction: ATP + (R)-pantothenate = ADP + (R)-4′-phosphopantothenate
Other name(s): pantothenate kinase (phosphorylating); pantothenic acid kinase; ATP:pantothenate 4′-phosphotransferase; D-pantothenate kinase
Systematic name: ATP:(R)-pantothenate 4′-phosphotransferase
1.  Abiko, Y., Ashida, S.-I. and Shimizu, M. Purification and properties of D-pantothenate kinase from rat liver. Biochim. Biophys. Acta 268 (1972) 364–372. [PMID: 4337331]
2.  Brown, G.M. The metabolism of pantothenic acid. J. Biol. Chem. 234 (1959) 370–378. [PMID: 13630913]
3.  Pierpoint, W.S., Hughes, D.E., Baddiley, J. and Mathias, A.P. The phosphorylation of pantothenic acid by Lactobacillus arabinosus 17-5. Biochem. J. 61 (1955) 368–374. [PMID: 13269369]
[EC created 1961]
Accepted name: pantothenase
Reaction: (R)-pantothenate + H2O = (R)-pantoate + β-alanine
Other name(s): pantothenate hydrolase; pantothenate amidohydrolase
Systematic name: (R)-pantothenate amidohydrolase
1.  Nurmikko, V., Salo, E., Hakola, H., Makinen, K. and Snell, E.E. The bacterial degradation of pantothenic acid. II. Pantothenate hydrolase. Biochemistry 5 (1966) 399–402. [PMID: 5940928]
[EC created 1972]
Accepted name: pantetheine hydrolase
Reaction: (R)-pantetheine + H2O = (R)-pantothenate + 2-aminoethanethiol
Other name(s): pantetheinase; vanin; vanin-1
Systematic name: (R)-pantetheine amidohydrolase
Comments: The enzyme hydrolyses only one of the amide bonds of pantetheine. The substrate analogues phosphopantetheine and CoA are not substrates. The enzyme recycles pantothenate (vitamin B5) and produces 2-aminoethanethiol (cysteamine), a potent anti-oxidant [5].
1.  Duprè, S. and Cavallini, D. Purification and properties of pantetheinase from horse kidney. Methods Enzymol. 62 (1979) 262–267. [PMID: 440106]
2.  Duprè, S., Chiaraluce, R., Nardini, M., Cannella, C., Ricci, G. and Cavallini, D. Continuous spectrophotometric assay of pantetheinase activity. Anal. Biochem. 142 (1984) 175–181. [PMID: 6549111]
3.  Maras, B., Barra, D., Duprè, S. and Pitari, G. Is pantetheinase the actual identity of mouse and human vanin-1 proteins? FEBS Lett. 461 (1999) 149–152. [PMID: 10567687]
4.  Aurrand-Lions, M., Galland, F., Bazin, H., Zakharyev, V.M., Imhof, B.A. and Naquet, P. Vanin-1, a novel GPI-linked perivascular molecule involved in thymus homing. Immunity 5 (1996) 391–405. [PMID: 8934567]
5.  Pitari, G., Malergue, F., Martin, F., Philippe, J.M., Massucci, M.T., Chabret, C., Maras, B., Duprè, S., Naquet, P. and Galland, F. Pantetheinase activity of membrane-bound Vanin-1: lack of free cysteamine in tissues of Vanin-1 deficient mice. FEBS Lett. 483 (2000) 149–154. [PMID: 11042271]
6.  Martin, F., Malergue, F., Pitari, G., Philippe, J.M., Philips, S., Chabret, C., Granjeaud, S., Mattei, M.G., Mungall, A.J., Naquet, P. and Galland, F. Vanin genes are clustered (human 6q22-24 and mouse 10A2B1) and encode isoforms of pantetheinase ectoenzymes. Immunogenetics 53 (2001) 296–306. [PMID: 11491533]
7.  Pace, H.C. and Brenner, C. The nitrilase superfamily: classification, structure and function. Genome Biol. 2 (2001) 0001.. [PMID: 11380987]
[EC created 2006]
Accepted name: pantoate—β-alanine ligase (AMP-forming)
Reaction: ATP + (R)-pantoate + β-alanine = AMP + diphosphate + (R)-pantothenate
Glossary: (R)-pantoate = (2R)-2,4-dihydroxy-3,3-dimethylbutanoate
(R)-pantothenate = 3-[(2R)-2,4-dihydroxy-3,3-dimethylbutanamido]propanoate
Other name(s): pantothenate synthetase; pantoate activating enzyme; pantoic-activating enzyme; D-pantoate:β-alanine ligase (AMP-forming); pantoate—β-alanine ligase (ambiguous)
Systematic name: (R)-pantoate:β-alanine ligase (AMP-forming)
1.  Ginoza, H.S. and Altenbern, R.A. The pantothenate-synthesizing enzyme cell-free extracts of Brucella abortus, strain 19. Arch. Biochem. Biophys. 56 (1955) 537–541. [PMID: 14377603]
2.  Maas, W.K. Pantothenate studies. III. Description of the extracted pantothenate-synthesizing enzyme of Escherichia coli. J. Biol. Chem. 198 (1952) 23–32. [PMID: 12999714]
3.  Maas, W.K. Mechanism of the enzymatic synthesis of pantothenate from β-alanine and pantoate. Fed. Proc. 15 (1956) 305–306.
[EC created 1961, modified 2014]
Accepted name: pantoate—β-alanine ligase (ADP-forming)
Reaction: ATP + (R)-pantoate + β-alanine = ADP + phosphate + (R)-pantothenate
Glossary: (R)-pantoate = (2R)-2,4-dihydroxy-3,3-dimethylbutanoate
(R)-pantothenate = 3-[(2R)-2,4-dihydroxy-3,3-dimethylbutanamido]propanoate
Other name(s): pantothenate synthetase (ambiguous); pantoate—β-alanine ligase (ambiguous)
Systematic name: (R)-pantoate:β-alanine ligase (ADP-forming)
Comments: The enzyme, characterized from the archaeon Methanosarcina mazei, is involved in the biosynthesis of pantothenate. It is different from EC, the AMP-forming pantoate-β-alanine ligase found in bacteria and eukaryota.
1.  Ronconi, S., Jonczyk, R. and Genschel, U. A novel isoform of pantothenate synthetase in the Archaea. FEBS J. 275 (2008) 2754–2764. [PMID: 18422645]
[EC created 2014]