Carbon dioxide (CO) 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 CO in vitro. The crotonyl-coenzyme A (CoA)/ethylmalonyl-CoA/hydroxybutyryl-CoA (CETCH) cycle is a reaction network of 17 enzymes that converts CO into organic molecules at a rate of 5 nanomoles of CO 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 CO fixation pathways, thereby opening the way for in vitro and in vivo applications.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5892708 | PMC |
http://dx.doi.org/10.1126/science.aah5237 | DOI Listing |
Synth Biol (Oxf)
September 2024
Department of Biochemistry & Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, Marburg 35043, Germany.
metabolic systems allow the reconstitution of natural and new-to-nature pathways outside of their cellular context and are of increasing interest in bottom-up synthetic biology, cell-free manufacturing, and metabolic engineering. Yet, the analysis of the activity of such networks is very often restricted by time- and cost-intensive methods. To overcome these limitations, we sought to develop an transcription (IVT)-based biosensing workflow that is compatible with the complex conditions of metabolism, such as the crotonyl-CoA/ethylmalonyl-CoA/hydroxybutyryl-CoA (CETCH) cycle, a 27-component metabolic system that converts CO into glycolate.
View Article and Find Full Text PDFBioorg Chem
December 2024
Bioengineering Department, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia; Interdisciplinary Research Center for Hydrogen Technologies and Carbon Management, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, 31261, Saudi Arabia; Biosystems and Machines Research Center, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, 31261, Saudi Arabia. Electronic address:
In most organisms, the tri-carboxylic acid cycle (TCA cycle) is an essential metabolic system that is involved in both energy generation and carbon metabolism. Its uni-directionality, however, restricts its use in synthetic biology and carbon fixation. Here, it is describing the use of the modified TCA cycle, called the Tri-carboxylic acid Hooked to Ethylene by Enzyme Reactions and Amino acid Synthesis, the reductive tricarboxylic acid branch/4-hydroxybutyryl-CoA/ethylmalonyl-CoA/acetyl-CoA (THETA) cycle, in Escherichia coli for the purposes of carbon fixation and amino acid synthesis.
View Article and Find Full Text PDFCold Spring Harb Perspect Biol
February 2024
Max Planck Society, Germany, Department for Biochemistry & Synthetic Metabolism, Center for Synthetic Microbiology (SYNMIKRO) & Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
Synthetic biology provides opportunities to realize new-to-nature CO-fixation metabolisms to overcome the limitations of natural photosynthesis. Two different strategies are currently being pursued: One is to realize engineered plants that feature carbon-neutral or carbon-negative (i.e.
View Article and Find Full Text PDFBiochemistry
June 2023
Department of Biochemistry & Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043 Marburg, Germany.
Succinyl-CoA reductase (SucD) is an acylating aldehyde reductase that catalyzes the NADPH-dependent reduction of succinyl-CoA to succinic semialdehyde. The reaction sequence from succinate to crotonyl-CoA is of particular interest for several new-to-nature CO-fixation pathways, such as the crotonyl-CoA/ethylmalonyl-CoA/hydroxybutyryl-CoA (CETCH) cycle, in which SucD plays a key role. However, pathways like the CETCH cycle feature several CoA-ester intermediates, which could be potentially side substrates for this enzyme.
View Article and Find Full Text PDFNat Chem Biol
February 2023
Department of Biochemistry and Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
Anaplerosis is an essential feature of metabolism that allows the continuous operation of natural metabolic networks, such as the citric acid cycle, by constantly replenishing drained intermediates. However, this concept has not been applied to synthetic in vitro metabolic networks, thus far. Here we used anaplerotic strategies to directly access the core sequence of the CETCH cycle, a new-to-nature in vitro CO-fixation pathway that features several C-C biosynthetic precursors.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!