One the observation of three bands in the region of "core proteins" on SDS gels of potato bc1 complex: 1991 Berry et al. JBC 266, 9064-9077: If the three bands actually represent three different pep- tides present in the potato and beet bcl complex, it still remains to be decided whether each molecule of complex contains three core peptides or each contains two peptides, one of which exists in either of two different iso-forms. (...) The heme content supports heterogeneity of one polypep- tide between complexes because, as was explained under heme content, there is not enough protein for each of the 10 subunits observed to be present in a stoichiometry of 1 per heme c. Heterogeneity has been reported for core protein 2 of yeast bc, complex (88). Heterogeneity could result from heterozy- gosity, from tissue or developmental stage specificity, or from heterogeneity of post-translational processing. ---------------------------------------------------------------- 1992 Braun HP, Schmitz UK. Eur J Biochem 208:761-7 (abstract) Interestingly, an additional 'core' polypeptide which is not present in other cytochrome bc1 complexes forms part of the enzyme from potato. ...potato cytochrome c reductase is about 100 kDa larger than the fungal enzyme. This may be due to the association of an additional 'core' protein with the potato complex. ... Alternatively, two of the three bands may be isoforms of the same protein, as proposed by Berry et al. However, antibodies directed against the 53 kDa and 51 kDa subunits of the potato complex exclusively recognize the proteins used for immunization and do not cross-react with other subunits. These data suggest that three distinct core proteins form part of potato cytochrome bc1 complex. ---------------------------------------------------------------- 1992 Braun HP, Emmermann M, Kruft V, Schmitz UK. EMBO J 11:3219-27 (abstract) Protein sequencing of peptides from individual subunits and analysis of corresponding cDNA clones reveals that subunit III of cytochrome c reductase (51 kDa) represents the general mitochondrial processing peptidase. ---------------------------------------------------------------- 1993 Emmermann M, Braun HP, Arretz M, Schmitz UK. J Biol Chem. 268:18936-42. (subunits 1 and 2 are both like PEP) ---------------------------------------------------------------- 1995 Jansch L, Kruft V, Schmitz UK, Braun HP. Eur J Biochem 228(3):878-85 Cytochrome c reductase from potato does not comprise three core proteins but contains an additional low-molecular-mass subunit. ---------------------------------------------------------------- Come on, guys, how about ", as suggested by Berry et al. 1991, and contrary to the conclusions of Braun et al. 1992"?