Genes essential for phototrophic growth by a purple alphaproteobacterium
Abstract
Tn‐seq was used to identify genes essential for phototrophic growth by the purple bacterium Rhodopseudomonas palustris. About 167 genes required for anaerobic growth on acetate in light were identified, 35 of which are annotated as photosynthesis genes. The essentiality of many of these genes by analysing the phenotypes of independently generated mutants that had altered pigmentation was verified. Three genes were identified, two possibly involved in biogenesis of the membrane‐bound photosynthetic apparatus and one for phosphatidylcholine biosynthesis, that were not known to be essential for phototrophic growth. Site‐directed mutagenesis was used to show that the NADH:quinone oxidoreductase complex IE was essential for phototrophic growth under strictly anaerobic conditions and appeared to play a role in reverse electron transport to generate NADH. A homologous NADH:quinone oxidoreductase complex IA likely operates in the opposite direction to oxidize NADH. The operation of the two enzymes in opposition would allow R. palustris to maintain redox balance. As a complement to the genetic data, proteomics experiments were carried out in which it was found that 408 proteins were present in significantly higher amounts in cells grown anaerobically in light compared with aerobically. Among these were proteins encoded by subset of the phototrophic growth‐essential genes.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 24, 2017
- Source ID
- 10.1111/1462-2920.13852
Entities
People
- Caroline S. Harwood
- Ernesto S. Nakayasu
- Faith H. Lessner
- Jianming Yang
- Kathryn R Fixen
- Larry Gallagher
- Liang Yin
- Samuel H Payne
Organizations
- Army Research Office
- Office of Biological and Environmental Research
- Pacific Northwest National Laboratory
- Qingdao Agricultural University
- United States Department of Energy
- University of Arkansas
- University of Washington