NADH dehydrogenase (quinone)

NADH dehydrogenase (quinone)
Structure of NADH dehydrogenase (quinone). PDB entry 3iam[1]
Identifiers
EC number	1.6.99.5
CAS number	37256-36-3
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / EGO
Search PMC articles PubMed articles NCBI proteins

In enzymology, a NADH dehydrogenase (quinone) (EC 1.6.99.5) is an enzyme that catalyzes the chemical reaction

NADH + H⁺ + acceptor $\rightleftharpoons$ NAD⁺ + reduced acceptor

The 3 substrates of this enzyme are NADH, H⁺, and acceptor, whereas its two products are NAD⁺ and reduced acceptor.

This enzyme belongs to the family of oxidoreductases, specifically those acting on NADH or NADPH with other acceptors. The systematic name of this enzyme class is NADH:(quinone-acceptor) oxidoreductase. Other names in common use include reduced nicotinamide adenine dinucleotide (quinone) dehydrogenase, NADH-quinone oxidoreductase, NADH ubiquinone oxidoreductase, DPNH-menadione reductase, D-diaphorase, and NADH2 dehydrogenase (quinone), and mitochondrial (mt) complex I. This enzyme participates in oxidative phosphorylation. Several compounds are known to inhibit this enzyme, including AMP, and 2,4-Dinitrophenol.

Structural studies

Several structures are available of this enzyme, which is part of the respiratory chain. It is a multi-subunit enzyme in which this activity is located in the hydrophilic domain. The subunits of the membrane-embedded domain are responsible for proton translocation.

References

1. Berrisford JM1, Sazanov LA. (2009). "Structural basis for the mechanism of respiratory complex I". J Biol Chem. 284 (43): 29773–83. doi:10.1074/jbc.M109.032144. PMID 19635800.

• Koli AK, Yearby C, Scott W, Donaldson KO (1969). "Purification and properties of three separate menadione reductases from hog liver". J. Biol. Chem. 244 (4): 621–9. PMID 4388793.