TRNA-dihydrouridine20a/20b synthase (NAD(P)+)

TRNA-dihydrouridine20a/20b synthase (NAD(P)) (EC 1.3.1.90, Dus4p) is an enzyme with systematic name tRNA-5,6-dihydrouracil20a/20b:NAD(P) oxidoreductase. This enzyme catalyses the following chemical reaction

(1) 5,6-dihydrouracil20a in tRNA + NAD(P)

\rightleftharpoons

uracil20a in tRNA + NAD(P)H + H

(2) 5,6-dihydrouracil20b in tRNA + NAD(P)

\rightleftharpoons

uracil20b in tRNA + NAD(P)H + H

A flavoenzyme. The enzyme specifically modifies uracil20a and uracil20b in tRNA.

References

Xing F, Hiley SL, Hughes TR, Phizicky EM (April 2004). "The specificities of four yeast dihydrouridine synthases for cytoplasmic tRNAs". The Journal of Biological Chemistry. 279 (17): 17850–60. doi:10.1074/jbc.M401221200. PMID 14970222.

v t e Oxidoreductases: CH–CH oxidoreductases (EC 1.3)
1.3.1: NAD/NADP acceptor	Enoyl-acyl carrier protein reductase/Enoyl ACP reductase 7-Dehydrocholesterol reductase Biliverdin reductase 2,4 Dienoyl-CoA reductase Dihydroxymethyloxo-tetrahydroquinoline dehydrogenase
1.3.3: Oxygen acceptor	Dihydroorotate dehydrogenase Coproporphyrinogen III oxidase Protoporphyrinogen oxidase Bilirubin oxidase Acyl-CoA oxidase Dihydrouracil oxidase Tetrahydroberberine oxidase Secologanin synthase Tryptophan alpha,beta-oxidase Pyrroloquinoline-quinone synthase L-galactonolactone oxidase
1.3.5: Quinone	Succinate dehydrogenase SDHA SDHB SDHC SDHD
1.3.99: Other acceptors	Fumarate reductase Butyryl-CoA dehydrogenase Acyl CoA dehydrogenase ACADSB ACADS 5α-reductase SRD5A1 SRD5A2 SRD5A3 Glutaryl-CoA dehydrogenase Isovaleryl coenzyme A dehydrogenase 3-oxo-5beta-steroid 4-dehydrogenase

v t e Enzymes
Activity	Active site Binding site Catalytic triad Oxyanion hole Enzyme promiscuity Diffusion-limited enzyme Cofactor Enzyme catalysis
Regulation	Allosteric regulation Cooperativity Enzyme inhibitor Enzyme activator
Classification	EC number Enzyme superfamily Enzyme family List of enzymes
Kinetics	Enzyme kinetics Eadie–Hofstee diagram Hanes–Woolf plot Lineweaver–Burk plot Michaelis–Menten kinetics
Types	EC1 Oxidoreductases (list) EC2 Transferases (list) EC3 Hydrolases (list) EC4 Lyases (list) EC5 Isomerases (list) EC6 Ligases (list) EC7 Translocases (list)