ABSTRACT
CII consists of a hydrophilic catalytic heterodimer containing avin adenine dinucleotide and three iron-sulphur clusters. is domain is connected to a transmembrane domain composed of two hydrophobic subunits containing one heme b and the UQ-binding site located proximal to the matrix side of the membrane. e enzyme oxidizes succinate and transfers electrons through iron-sulphur clusters to UQ without generating a proton gradient across the membrane (Sun et al. 2005).
