Enzymes
UniProtKB help_outline | 6 proteins |
Enzyme class help_outline |
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- Name help_outline ATP Identifier CHEBI:30616 (Beilstein: 3581767) help_outline Charge -4 Formula C10H12N5O13P3 InChIKeyhelp_outline ZKHQWZAMYRWXGA-KQYNXXCUSA-J SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OP([O-])([O-])=O)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,256 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline NADH Identifier CHEBI:57945 (Beilstein: 3869564) help_outline Charge -2 Formula C21H27N7O14P2 InChIKeyhelp_outline BOPGDPNILDQYTO-NNYOXOHSSA-L SMILEShelp_outline NC(=O)C1=CN(C=CC1)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](O)[C@@H]2O)n2cnc3c(N)ncnc23)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,073 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline ADP Identifier CHEBI:456216 (Beilstein: 3783669) help_outline Charge -3 Formula C10H12N5O10P2 InChIKeyhelp_outline XTWYTFMLZFPYCI-KQYNXXCUSA-K SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])([O-])=O)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 835 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,176 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline NADPH Identifier CHEBI:57783 (Beilstein: 10411862) help_outline Charge -4 Formula C21H26N7O17P3 InChIKeyhelp_outline ACFIXJIJDZMPPO-NNYOXOHSSA-J SMILEShelp_outline NC(=O)C1=CN(C=CC1)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](OP([O-])([O-])=O)[C@@H]2O)n2cnc3c(N)ncnc23)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,247 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:12260 | RHEA:12261 | RHEA:12262 | RHEA:12263 | |
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Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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Identification, molecular cloning and functional characterization of a novel NADH kinase from Arabidopsis thaliana (thale cress).
Turner W.L., Waller J.C., Snedden W.A.
NADH kinase (NADHK; ATP:NADH 2'-phosphotransferase; EC 2.7.1.86), an enzyme that preferentially utilizes NADH as the diphosphonicotinamide nucleotide donor, has been identified for the first time in plants. Low activity (0.4 nmol of NADPH produced/min per mg of protein) was observed in clarified p ... >> More
NADH kinase (NADHK; ATP:NADH 2'-phosphotransferase; EC 2.7.1.86), an enzyme that preferentially utilizes NADH as the diphosphonicotinamide nucleotide donor, has been identified for the first time in plants. Low activity (0.4 nmol of NADPH produced/min per mg of protein) was observed in clarified protein extracts from Arabidopsis thaliana (thale cress) cell suspension cultures. However, unlike an NADHK from yeast (Saccharomyces cerevisiae) (POS5), the enzyme from Arabidopsis did not associate with the mitochondria. NADHK was cloned (gi:30699338) from Arabidopsis and studied as a recombinant protein following affinity purification from Escherichia coli. The enzyme had a pH optimum for activity of 7.9 and a subunit molecular mass of 35 kDa. Analytical gel filtration demonstrated that the recombinant enzyme exists as a dimer. Hyperbolic saturation kinetics were observed for the binding of NADH, ATP, free Mg2+ and NAD+, with respective K(m) values of 0.042, 0.062, 1.16, and 2.39 mM. While NADHK could phosphorylate NADH or NAD+, the specificity constant (V(max)/K(m)) for NADH was 100-fold greater than for NAD+. The enzyme could utilize UTP, GTP and CTP as alternative nucleotides, although ATP was the preferred substrate. PP(i) or poly-P(i) could not substitute as phospho donors. PP(i) acted as a mixed inhibitor with respect to both NADH and ATP. NADHK was inactivated by thiol-modifying reagents, with inactivation being decreased in the presence of NADH or ATP, but not NAD+. This study suggests that, in Arabidopsis, NADP+/NADPH biosynthetic capacity could, under some circumstances, become uncoupled from the redox status of the diphosphonicotinamide nucleotide pool. << Less
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Synthetic lethal and biochemical analyses of NAD and NADH kinases in Saccharomyces cerevisiae establish separation of cellular functions.
Bieganowski P., Seidle H.F., Wojcik M., Brenner C.
Production of NADP and NADPH depends on activity of NAD and NADH kinases. Here we characterized all combinations of mutants in yeast NAD and NADH kinases to determine their physiological roles. We constructed a diploid strain heterozygous for disruption of POS5, encoding mitochondrial NADH kinase, ... >> More
Production of NADP and NADPH depends on activity of NAD and NADH kinases. Here we characterized all combinations of mutants in yeast NAD and NADH kinases to determine their physiological roles. We constructed a diploid strain heterozygous for disruption of POS5, encoding mitochondrial NADH kinase, UTR1, cytosolic NAD kinase, and YEF1, a UTR1-homologous gene we characterized as encoding a low specific activity cytosolic NAD kinase. pos5 utr1 is a synthetic lethal combination rescued by plasmid-borne copies of the POS5 or UTR1 genes or by YEF1 driven by the ADH1 promoter. Respiratory-deficient and oxidative damage-sensitive defects in pos5 mutants were not made more deleterious by yef1 deletion, and a quantitative growth phenotype of pos5 and its arginine auxotrophy were repaired by plasmid-borne POS5 but not UTR1 or ADH1-driven YEF1. utr1 haploids have a slow growth phenotype on glucose not exacerbated by yef1 deletion but reversed by either plasmid-borne UTR1 or ADH1-driven YEF1. The defect in fermentative growth of utr1 mutants renders POS5 but not POS5-dependent mitochondrial genome maintenance essential because rho-utr1 derivatives are viable. Purified Yef1 has similar nucleoside triphosphate specificity but substantially lower specific activity and less discrimination in favor of NAD versus NADH phosphorylation than Utr1. Low expression and low intrinsic NAD kinase activity of Yef1 and the lack of phenotype associated with yef1 suggest that Utr1 and Pos5 are responsible for essentially all NAD/NADH kinase activity in vivo. The data are compatible with a model in which there is no exchange of NADP, NADPH, or cytoplasmic NAD/NADH kinase between nucleocytoplasmic and mitochondrial compartments, but the cytoplasm is exposed to mitochondrial NAD/NADH kinase during the transit of the molecule. << Less
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Identification of ATP-NADH kinase isozymes and their contribution to supply of NADP(H) in Saccharomyces cerevisiae.
Shi F., Kawai S., Mori S., Kono E., Murata K.
ATP-NAD kinase phosphorylates NAD to produce NADP by using ATP, whereas ATP-NADH kinase phosphorylates both NAD and NADH. Three NAD kinase homologues, namely, ATP-NAD kinase (Utr1p), ATP-NADH kinase (Pos5p) and function-unknown Yel041wp (Yef1p), are found in the yeast Saccharomyces cerevisiae. In ... >> More
ATP-NAD kinase phosphorylates NAD to produce NADP by using ATP, whereas ATP-NADH kinase phosphorylates both NAD and NADH. Three NAD kinase homologues, namely, ATP-NAD kinase (Utr1p), ATP-NADH kinase (Pos5p) and function-unknown Yel041wp (Yef1p), are found in the yeast Saccharomyces cerevisiae. In this study, Yef1p was identified as an ATP-NADH kinase. The ATP-NADH kinase activity of Utr1p was also confirmed. Thus, the three NAD kinase homologues were biochemically identified as ATP-NADH kinases. The phenotypic analysis of the single, double and triple mutants, which was unexpectedly found to be viable, for UTR1, YEF1 and POS5 demonstrated the critical contribution of Pos5p to mitochondrial function and survival at 37 degrees C and the critical contribution of Utr1p to growth in low iron medium. The contributions of the other two enzymes were also demonstrated; however, these were observed only in the absence of the critical contributor, which was supported by complementation for some pos5 phenotypes by the overexpression of UTR1 and YEF1. The viability of the triple mutant suggested that a 'novel' enzyme, whose primary structure is different from those of all known NAD and NADH kinases, probably catalyses the formation of cytosolic NADP in S. cerevisiae. Finally, we found that LEU2 of Candida glabrata, encoding beta-isopropylmalate dehydrogenase and being used to construct the triple mutant, complemented some pos5 phenotypes; however, overexpression of LEU2 of S. cerevisiae did not. The complementation was putatively attributed to an ability of Leu2p of C. glabrata to use NADP as a coenzyme and to supply NADPH. << Less