The cytochrome b lysine 329 residue is critical for ubihydroquinone oxidation and proton release at the Q_o site of bacterial cytochrome bc₁.

ABSTRACT: The ubihydroquinone:cytochrome (cyt) c oxidoreductase (or cyt bc₁) is an important enzyme for photosynthesis and respiration. In bacteria like Rhodobacter capsulatus, this membrane complex has three subunits, the iron‑sulfur protein (ISP) with its Fe₂S₂ cluster, cyt c₁ and cyt b, forming two catalytic domains, the Q_o (hydroquinone (QH₂) oxidation) and Q_i (quinone (Q) reduction) sites. At the Q_o site, the electron transfer pathways originating from QH₂ oxidation are known, but their associated proton release routes are less well defined. Earlier, we demonstrated that the His291 of cyt b is important for this latter process. In this work, using the bacterial cyt bc₁ and site directed

SUBMITTER: Francia F 

PROVIDER: S-EPMC6317905 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature