The position and interaction of cytochrome b with the electron transport chain in green plant photosynthesis has remained obscure. Levine et al. (13) and Levine and Gorman (12) first demonstrated the presence of cytochrome b. in the photosynthetic electron transport chain. Their results (12, 13), showing that photosystem II reduced cytochrome b, but that it was oxidized by PS I' in a DCMU-insen...

DNA sequence studies of cytochrome b(5) (Cyt-b) genes from Drosophila melanogaster and Drosophila virilis predict that the Drosophila Cyt-b proteins are extremely hydrophobic and have at least eight potential transmembrane spanning domains. Primary protein sequence analysis also predicts that the Cyt-b proteins have mitochondrial targeting sequences and they contain sites for potential post-tra...

Activation of the phagocyte NADPH oxidase complex requires the assembly of the cytosolic factors p47(PHOX), p67(PHOX), p40(PHOX), and Rac1 or Rac2, with the membrane-bound cytochrome b(558). Whereas the interaction of p47(PHOX) with cytochrome b(558) is well established, an interaction between p67(PHOX) and cytochrome b(558) has never been investigated. We report here a direct interaction betwe...

Membrane-bound nitrate reductase purified from Escherichia coli was resolved into two separate forms. The majority of the enzyme complex had a subunit composition of 2A:2B:4C, exhibited cytochrome b spectra, and was found to be stable after purification. A second form of nitrate reductase activity was a modified complex with a subunit composition of 2A:2B and lacked cytochrome. The subunit B fr...

The major iron-containing respiratory pigment of Corynebacterium diphtheriae is spectroscopically related to cytochrome b (l-3). In a previous communication (2) we presented evidence which suggests that diphtheria toxin may be closely related to the protein moiety of diphtherial eytochrome b. The tentative hypothesis was advanced that diphtheria toxin may act by interfering with the normal func...

We have obtained evidence for electron transfer between cytochrome b subunits of the yeast bc(1) complex dimer by analyzing pre-steady state reduction of cytochrome b in the presence of center P inhibitors. The kinetics and extent of cytochrome b reduced by quinol in the presence of variable concentrations of antimycin decreased non-linearly and could only be fitted to a model in which electron...