FUNCTIONAL COMPLEMENTATION OF A CYTOCHROME c OXIDASE MUTANT OF SYNECHOCYSTIS SP. PCC 6803

摘要

Cytochrome c oxidase is one of the enzymes catalyzing reduction of molecular oxygen in respiration in Synechocystis sp. PCC 6803. Deletion of the gene coding for subunit I of this enzyme (sir1137) impacts the ability of the organism to grow at low light intensity (Pils et al 1997). This probably is a result of over-reduction of the PQ pool that cannot be alleviated by the photosynthetic activity of photosysem I (PS I). Therefore, the cytochrome c oxidase deletion mutant (Ctal-less strain) is a good model to study regulation of the redox state of the PQ pool in this cyanobacterium. One of the approaches used in this study involves the selection of a pseudorevertant of the Ctal-less strain that can grow at low light intensity but retains the originaldeletion of sir 1137.