NADH dehydrogenase [ubiquinone] iron-sulfur protein 2, mitochondrial also known as NADH-ubiquinone oxidoreductase 49 kDa subunit is an enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

 that in humans is encoded by the NDUFS2 gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

.

Function

Mitochondrial

Mitochondrion

In cell biology, a mitochondrion is a membrane-enclosed organelle found in most eukaryotic cells. These organelles range from 0.5 to 1.0 micrometers in diameter...

 complex I

NADH dehydrogenase

NADH dehydrogenase is an enzyme located in the inner mitochondrial membrane that catalyzes the transfer of electrons from NADH to coenzyme Q...

 is the first multimeric complex of the respiratory chain

Electron transport chain

An electron transport chain couples electron transfer between an electron donor and an electron acceptor with the transfer of H+ ions across a membrane. The resulting electrochemical proton gradient is used to generate chemical energy in the form of adenosine triphosphate...

 that catalyzes the NADH oxidation with concomitant ubiquinone reduction and proton ejection out of the mitochondria. Mammalian mitochondrial complex I is an assembly of at least 43 different subunits. Seven of the subunits are encoded by the mitochondrial genome

Mitochondrial DNA

Mitochondrial DNA is the DNA located in organelles called mitochondria, structures within eukaryotic cells that convert the chemical energy from food into a form that cells can use, adenosine triphosphate...

; the remainder are the products of nuclear genes. The iron-sulfur protein

Iron-sulfur protein

Iron-sulfur proteins are proteins characterized by the presence of iron-sulfur clusters containing sulfide-linked di-, tri-, and tetrairon centers in variable oxidation states...

(IP) fraction of complex I is made up of 7 subunits, including NDUFS2.