The NADH dehydrogenase
complex, also called NADH coenzyme Q oxidoreductase
, is the first complex in the electron transfer chain
and catalyzes the transfer of electrons
from NADH to coenzyme Q
- NADH + CoQ + H+ → NAD+ + CoQH2
In the process of reducing coenzyme Q, this complex also translocates protons
, helping to provide the electrochemical potential
used to produce ATP
. It is a large complex, the mammalian enzyme containing 43 separate protein subunits, as well as a flavin
prosthetic group and several iron-sulfur clusters.
Seven of the 43 mammalian protein subunits are encoded in the mitochondrial DNA. Defects in the subunits of Complex I are associated with various mitochondrial diseases.
More information can be found on the Complex I home page.