* Complex I is one of the largest membrane proteins in the cell.
* The structure of complex I in prokaryotic contains 14 subunits, has L shaped structure with mixture of a helices, beta strands and loops, is classified into 2 domains, hydrophilic domain is termed by peripheral arm, and hydrophobic domain which is termed by membrane domain. The peripheral arm structure solved at 3.3 angstrom.
* Mutations in Complex I genes in humans lead to vision loss, brain dysfunction, or loss of muscle function, and such disorders are commonly due to the poor assembly of Complex I.
| Overall structure | Page 1 | |
| NADH and FMN binding | Page 2 | |
| Stability and Mutations | Page 3 | |
| Complex I activity | Page 4 | |
| Interface between peripheral arm and membrane domain | Page 5 |