NADH dehydrogenase

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NADH dehydrogenase

NADH dehydrogenase (ubiquinone) Fe-S protein 1, 75kDa (NADH-coenzyme Q reductase)
Identifiers
Symbol(s)	NDUFS1
Entrez	4719
OMIM	157655
RefSeq	NM_005006
UniProt	P28331
Other data
EC number	1.6.5.3
Locus	Chr. 2 q33-q34

NADH dehydrogenase (ubiquinone) Fe-S protein 2, 49kDa (NADH-coenzyme Q reductase)
Identifiers
Symbol(s)	NDUFS2
Entrez	4720
OMIM	602985
RefSeq	NM_004550
UniProt	O75306
Other data
EC number	1.6.5.3
Locus	Chr. 1 q23.3

NADH dehydrogenase (ubiquinone) flavoprotein 1, 51kDa
Identifiers
Symbol(s)	NDUFV1
Entrez	4723
OMIM	161015
RefSeq	NM_007103
UniProt	P49821
Other data
EC number	1.6.5.3
Locus	Chr. 11 q13

NADH dehydrogenase (ubiquinone) flavoprotein 2, 24kDa
Identifiers
Symbol(s)	NDUFV2
Entrez	4729
OMIM	600532
RefSeq	NM_021074
UniProt	P19404
Other data
EC number	1.6.5.3
Locus	Chr. 18 p11.22-11.21

NADH dehydrogenase (ubiquinone) flavoprotein 3, 10kDa
Identifiers
Symbol(s)	NDUFV3
Entrez	4731
OMIM	602184
RefSeq	NM_001001503
UniProt	P56181
Other data
EC number	1.6.5.3
Locus	Chr. 21 q22.3

mitochondrially encoded NADH dehydrogenase 4
Identifiers
Symbol(s)	MT-ND4 MTND4
Entrez	4538
OMIM	516003
RefSeq	[1]
UniProt	[2]
Other data
EC number	1.6.5.3
Locus	Chr. mitochondria [3]

NADH dehydrogenase (EC 1.6.5.3), Complex I of the mitochondrial electron transfer chain, catalyzes the transfer of electrons from NADH to coenzyme Q (CoQ). It is also known as the NADH:Ubiquinone oxidoreductase.

2NADH + CoQ + 2H⁺ → 2NAD⁺ + CoQH₂

In the process, the complex also translocates protons across the inner membrane, helping to build the electrochemical potential used to produce ATP. The exact catalytic mechanism remains unknown.

It is the largest of the respiratory complexes, the mammalian enzyme containing 45 separate polypeptide chains. Of particular functional importance are the flavin prosthetic group and eight iron-sulfur clusters. Of the 45 subunits, seven are encoded by the mitochondrial genome. The exact structure is presently unknown.

Mutations in the subunits of Complex I can cause mitochondrial diseases, including Leigh syndrome. There is some evidence that Complex I defects may play a role in the etiology of Parkinson's disease, perhaps because of reactive oxygen species (Complex I can, like Complex III, leak electron to Oxygen, forming highly toxic superoxide).

The best known inhibitor of Complex I is Rotenone (used as an organic pesticide). It is thought to bind to the ubiquinone binding site. Piericidin A is a more potent inhibitor and is a close structural homologue of ubiquinone.