title: Exposing the complex III Qo semiquinone radical.
abstract: Complex III Qo site semiquinone has been assigned pivotal roles in productive energy-conversion and destructive superoxide generation. After a 30-year search, a genetic heme bH knockout arrests this transient semiquinone EPR radical, revealing the natural engineering balance pitting energy-conserving, short-circuit minimizing, split electron transfer and catalytic speed against damaging oxygen reduction.
authors.affiliation: Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Haibo
authors.initials: H
authors.lastname: Zhang
authors.forename: Artur
authors.initials: A
authors.lastname: Osyczka
authors.forename: P Leslie
authors.initials: PL
authors.lastname: Dutton
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Moser
mesh_terms: D016227:Benzoquinones / Q000737:chemistry*; D003573:Cytochrome b Group / Q000737:chemistry / Q000235:genetics; D014450:Electron Transport Complex III / Q000737:chemistry*; D008928:Mitochondria / Q000201:enzymology*; D010084:Oxidation-Reduction; D016354:Rhodobacter capsulatus / Q000201:enzymology / Q000235:genetics
chemical_list: D016227:Benzoquinones; D003573:Cytochrome b Group; C025232:semiquinone radicals; D014450:Electron Transport Complex III