Complex I is the largest protein complex of the oxidative phosphorylation system in mitochondrial and it catalyzes NADH-quinone oxidoreduction. Complex I represents the main entrance site for electrons into the respiratory electron transfer chain. In Arabidopsis, Complex I have at least 49 subunits and NAD5 (ATMG00060/ATMG00513/ATMG00665) is one of the subunit.
