EC - Proton-translocating NAD(P)+ transhydrogenase

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IntEnz Enzyme Nomenclature


Accepted name:
proton-translocating NAD(P)+ transhydrogenase
Other names:
pntA (gene name)
pntB (gene name)
NNT (gene name)
Systematic name:
NADPH:NAD+ oxidoreductase (H+-transporting)



The enzyme is a membrane bound proton-translocating pyridine nucleotide transhydrogenase that couples the reversible reduction of NADP by NADH to an inward proton translocation across the membrane. In the bacterium Escherichia coli the enzyme provides a major source of cytosolic NADPH. Detoxification of reactive oxygen species in mitochondria by glutathione peroxidases depends on NADPH produced by this enzyme. Formerly EC

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
UniProtKB/Swiss-Prot: (20) [show] [UniProt]


  1. Clarke, D. M., Bragg, P. D.
    Cloning and expression of the transhydrogenase gene of Escherichia coli.
    J. Bacteriol. 162 : 367-373 (1985). [PMID: 3884596]
  2. Clarke, D. M., Bragg, P. D.
    Purification and properties of reconstitutively active nicotinamide nucleotide transhydrogenase of Escherichia coli.
    Eur. J. Biochem. 149 : 517-523 (1985). [PMID: 3891338]
  3. Glavas, N. A., Hou, C., Bragg, P. D.
    Involvement of histidine-91 of the beta subunit in proton translocation by the pyridine nucleotide transhydrogenase of Escherichia coli.
    Biochemistry 34 : 7694-7702 (1995). [PMID: 7779816]
  4. Sauer, U., Canonaco, F., Heri, S., Perrenoud, A., Fischer, E.
    The soluble and membrane-bound transhydrogenases UdhA and PntAB have divergent functions in NADPH metabolism of Escherichia coli.
    J. Biol. Chem. 279 : 6613-6619 (2004). [PMID: 14660605]
  5. Bizouarn, T., Fjellstrom, O., Meuller, J., Axelsson, M., Bergkvist, A., Johansson, C., Goran Karlsson, B., Rydstrom, J.
    Proton translocating nicotinamide nucleotide transhydrogenase from E. coli. Mechanism of action deduced from its structural and catalytic properties.
    Biochim. Biophys. Acta 1457 : 211-228 (2000). [PMID: 10773166]
  6. White, S. A., Peake, S. J., McSweeney, S., Leonard, G., Cotton, N. P., Jackson, J. B.
    The high-resolution structure of the NADP(H)-binding component (dIII) of proton-translocating transhydrogenase from human heart mitochondria.
    Structure 8 : 1-12 (2000). [PMID: 10673423]
  7. Johansson, T., Oswald, C., Pedersen, A., Tornroth, S., Okvist, M., Karlsson, B. G., Rydstrom, J., Krengel, U.
    X-ray structure of domain I of the proton-pumping membrane protein transhydrogenase from Escherichia coli.
    J. Mol. Biol. 352 : 299-312 (2005). [PMID: 16083909]
  8. Meimaridou, E., Kowalczyk, J., Guasti, L., Hughes, C. R., Wagner, F., Frommolt, P., Nurnberg, P., Mann, N. P., Banerjee, R., Saka, H. N., Chapple, J. P., King, P. J., Clark, A. J., Metherell, L. A.
    Mutations in NNT encoding nicotinamide nucleotide transhydrogenase cause familial glucocorticoid deficiency.
    Nat. Genet. 44 : 740-742 (2012). [PMID: 22634753]

[EC created 2015 as EC, transferred 2018 to EC]