PROSITE documentation PDOC00843

Respiratory-chain NADH dehydrogenase (EC 1.6.5.3) [1,2] (also known as complex I or NADH-ubiquinone oxidoreductase) is an oligomeric enzymatic complex located in the inner mitochondrial membrane which also seems to exist in the chloroplast and in cyanobacteria (as a NADH-plastoquinone oxidoreductase). Among the 25 to 30 polypeptide subunits of this bioenergetic enzyme complex there is one with a molecular weight of 24 Kd (in mammals), which is a component of the iron-sulfur (IP) fragment of the enzyme. It seems to bind a 2Fe-2S iron-sulfur cluster. The 24 Kd subunit is nuclear encoded, as a precursor form with a transit peptide in mammals, and in Neurospora crassa.

The 24 Kd subunit is highly similar to [3,4]:

Subunit E of Escherichia coli NADH-ubiquinone oxidoreductase (gene nuoE).
Subunit NQO2 of Paracoccus denitrificans NADH-ubiquinone oxidoreductase.

As as signature pattern we selected a highly conserved region, located in the central section of this subunit and which contains two conserved cysteines that are probably involved in the binding of the 2Fe-2S center.

PROSITE is copyright. It is produced by the Swiss Institute of Bioinformatics (SIB). There are no restrictions on its use by non-profit institutions as long as its content is in no way modified. Usage by and for commercial entities requires a license agreement. For information about the licensing scheme send an email to license@isb-sib.ch or see: http://www.expasy.org/prosite/prosite_license.htm.

1	Authors	Ragan C.I.
1	Source	Curr. Top. Bioenerg. 15:1-36(1987).

2	Authors	Weiss H., Friedrich T., Hofhaus G., Preis D.
	Title	The respiratory-chain NADH dehydrogenase (complex I) of mitochondria.
	Source	Eur. J. Biochem. 197:563-576(1991).
	PubMed ID	2029890

3	Authors	Fearnley I.M., Walker J.E.
	Title	Conservation of sequences of subunits of mitochondrial complex I and their relationships with other proteins.
	Source	Biochim. Biophys. Acta 1140:105-134(1992).
	PubMed ID	1445936

4	Authors	Weidner U., Geier S., Ptock A., Friedrich T., Leif H., Weiss H.
	Title	The gene locus of the proton-translocating NADH: ubiquinone oxidoreductase in Escherichia coli. Organization of the 14 genes and relationship between the derived proteins and subunits of mitochondrial complex I.
	Source	J. Mol. Biol. 233:109-122(1993).
	PubMed ID	7690854

Respiratory-chain NADH dehydrogenase 24 Kd subunit signature

Description:

Last update:

Technical section:

References:

Copyright:

Miscellaneous: