NADH-ubiquinone oxidoreductase chain 4L/K (IPR001133)

Short name: NADH_UbQ_OxRdtase_chain4L/K

Overlapping homologous superfamilies


Family relationships


NADH:ubiquinone oxidoreductase (complex I) (EC: is a respiratory-chain enzyme that catalyses the transfer of two electrons from NADH to ubiquinone in a reaction that is associated with proton translocation across the membrane (NADH + ubiquinone = NAD+ + ubiquinol) [PMID: 1470679]. Complex I is a major source of reactive oxygen species (ROS) that are predominantly formed by electron transfer from FMNH(2). Complex I is found in bacteria, cyanobacteria (as a NADH-plastoquinone oxidoreductase), archaea [PMID: 10940377], mitochondria, and in the hydrogenosome, a mitochondria-derived organelle. In general, the bacterial complex consists of 14 different subunits, while the mitochondrial complex contains homologues to these subunits in addition to approximately 31 additional proteins [PMID: 18394423].

This entry represents NADH:ubiquinone oxidoreductase, chain 4L, as well as NADH-quinone oxidoreductase (EC: In eukaryotes, these enzymes are usually found in either mitochondria or chloroplasts as part of the respiratory-chain NADH dehydrogenase (also known as complex I or NADH-ubiquinone oxidoreductase), an oligomeric enzymatic complex [PMID: 15843018]. However, they are also found in bacteria [PMID: 18307315] and archaea [PMID: 10940377] where they are annotated as NuoK subunit.

GO terms

Biological Process

GO:0042773 ATP synthesis coupled electron transport
GO:0055114 oxidation-reduction process

Molecular Function

GO:0016651 oxidoreductase activity, acting on NAD(P)H

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.