Plastid terminal oxidase 2 (PTOX2) is the major oxidase involved in chlororespiration in Chlamydomonas.

ABSTRACT: By homology with the unique plastid terminal oxidase (PTOX) found in plants, two genes encoding oxidases have been found in the Chlamydomonas genome, PTOX1 and PTOX2. Here we report the identification of a knockout mutant of PTOX2. Its molecular and functional characterization demonstrates that it encodes the oxidase most predominantly involved in chlororespiration in this algal species. In this mutant, the plastoquinone pool is constitutively reduced under dark-aerobic conditions, resulting in the mobile light-harvesting complexes being mainly, but reversibly, associated with photosystem I. Accordingly, the ptox2 mutant shows lower fitness than wild type when grown under phototrophic conditions. Single and double mutants devoid of the cytochrome b(6)f complex and PTOX2 were used to measur

SUBMITTER: Houille-Vernes L 

PROVIDER: S-EPMC3251066 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature