A synthetic pathway for the fixation of carbon dioxide in vitro

• Published in: Science (American Association for the Advancement of Science) Vol. 354; no. 6314; pp. 900 - 904
• Main Authors: Schwander, Thomas, von Borzyskowski, Lennart Schada, Burgener, Simon, Cortina, Niña Socorro, Erb, Tobias J.
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 18.11.2016; The American Association for the Advancement of Science
• Subjects: Acyl Coenzyme A - chemistry; Acyl Coenzyme A - genetics; Arabidopsis - enzymology; Biomass; Biosynthetic Pathways; Carbon; Carbon - chemistry; Carbon Cycle; Carbon dioxide; Carbon Dioxide - chemistry; Chemical synthesis; Enzymes; Fixation; In vitro testing; Molecules; Organic Chemistry; Organisms; Oxidoreductases - chemistry; Oxidoreductases - genetics; Pathways; Protein Engineering; Rhodobacter sphaeroides - enzymology; Synthetic Biology
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.aah5237

Carbon dioxide (CO₂) is an important carbon feedstock for a future green economy. This requires the development of efficient strategies for its conversion into multicarbon compounds. We describe a synthetic cycle for the continuous fixation of CO₂ in vitro. The crotonyl-coenzyme A (CoA)/ethylmalonyl-CoA/hydroxybutyryl-CoA (CETCH) cycle is a reaction network of 17 enzymes that converts CO₂ into organic molecules at a rate of 5 nanomoles of CO₂ per minute per milligram of protein. The CETCH cycle was drafted by metabolic retrosynthesis, established with enzymes originating from nine different organisms of all three domains of life, and optimized in several rounds by enzyme engineering and metabolic proofreading. The CETCH cycle adds a seventh, synthetic alternative to the six naturally evolved CO₂ fixation pathways, thereby opening the way for in vitro and in vivo applications.