The unusual transhydrogenase of Entamoeba histolytica.
We have expressed and purified a protein fragment from Entamoeba histolytica. It catalyses transhydrogenation between analogues of NAD(H) and NADP(H). The characteristics of this reaction resemble those of the reaction catalysed by a complex of the NAD(H)- and NADP(H)-binding subunits of proton-translocating transhydrogenases from bacteria and mammals. It is concluded that the complete En. histolytica protein, which, along with similar proteins from other protozoan parasites, has an unusual subunit organisation, is also a proton-translocating transhydrogenase. The function of the transhydrogenase, thought to be located in organelles which do not have the enzymes of oxidative phosphorylation, is not clear.
Weston
C J
CJ
School of Biosciences, University of Birmingham, P.O. Box 363, Edgbaston, B15 2TT, Birmingham, UK.
White
S A
SA
Jackson
J B
JB
D000818:Animals; D002384:Catalysis; D004748:Entamoeba histolytica / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D009250:NADP Transhydrogenases / Q000737:chemistry / Q000378:metabolism*; D021122:Protein Subunits; D017494:Proton Pumps / Q000737:chemistry / Q000378:metabolism; D011522:Protons
D021122:Protein Subunits; D017494:Proton Pumps; D011522:Protons; D009243:NAD; D009249:NADP; D009250:NADP Transhydrogenases