Figure 3 The asymmetric unit of complex I, with atom labelling [symmetry codes: (i) −x + , y, −z + ; (ii) −x + 1, −y, −z + 2; (iii) −x + 1, −y + 1, −z + 2; (iv) −x + , y, −z + ; (v) x + 1, y, z]. Displacement ellipsoids are drawn at the 30% probability level.