On the origins of oxygenic photosynthesis and aerobic respiration in Cyanobacteria

• Published in: Science (American Association for the Advancement of Science) Vol. 355; no. 6332; pp. 1436 - 1440
• Main Authors: Soo, Rochelle M., Hemp, James, Parks, Donovan H., Fischer, Woodward W., Hugenholtz, Philip
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 31.03.2017; The American Association for the Advancement of Science
• Subjects: Aerobic respiration; Aerobiosis; Bacteria; Bacterial Proteins - classification; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Biological Evolution; Cyanobacteria; Cyanobacteria - classification; Cyanobacteria - enzymology; Cyanobacteria - genetics; Electron Transport Complex III - classification; Electron Transport Complex III - genetics; Electron Transport Complex III - metabolism; Electron Transport Complex IV - genetics; Electron Transport Complex IV - metabolism; Evolution; Evolutionary genetics; Genes; Genome, Bacterial; Genomes; Machinery and equipment; Origins; Oxygen - metabolism; Photosynthesis; Photosynthesis - genetics; Photosynthesis - physiology; Phylogeny; Prokaryotes; Respiration
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.aal3794

The origin of oxygenic photosynthesis in Cyanobacteria led to the rise of oxygen on Earth ~2.3 billion years ago, profoundly altering the course of evolution by facilitating the development of aerobic respiration and complex multicellular life. Here we report the genomes of 41 uncultured organisms related to the photosynthetic Cyanobacteria (class Oxyphotobacteria), including members of the class Melainabacteria and a new class of Cyanobacteria (class Sericytochromatia) that is basal to the Melainabacteria and Oxyphotobacteria. All members of the Melainabacteria and Sericytochromatia lack photosynthetic machinery, indicating that phototrophy was not an ancestral feature of the Cyanobacteria and that Oxyphotobacteria acquired the genes for photosynthesis relatively late in cyanobacterial evolution. We show that all three classes independently acquired aerobic respiratory complexes, supporting the hypothesis that aerobic respiration evolved after oxygenic photosynthesis.