biostudies-literatureMangan NMU.S. Department of EnergyEuropean Research CouncilE5354-62https://www.ebi.ac.uk/biostudies/studies/S-EPMC5018799biostudies-literatureUnknown113(36)Many carbon-fixing bacteria rely on a CO2 concentrating mechanism (CCM) to elevate the CO2 concentration around the carboxylating enzyme ribulose bisphosphate carboxylase/oxygenase (RuBisCO). The CCM is postulated to simultaneously enhance the rate of carboxylation and minimize oxygenation, a competitive reaction with O2 also catalyzed by RuBisCO. To achieve this effect, the CCM combines two features: active transport of inorganic carbon into the cell and colocalization of carbonic anhydrase and RuBisCO inside proteinaceous microcompartments called carboxysomes. Understanding the significance of the various CCM components requires reconciling biochemical intuition with a quantitative description of the system. To this end, we have developed a mathematical model of the CCM to analyze its enProceedings of the National Academy of Sciences of the United States of AmericapH determines the energetic efficiency of the cyanobacterial CO2 concentrating mechanism.PMC5018799DE-SC0006394NOVCARBFIX 646827646827Hood RDMangan NMSavage DFFlamholz AMilo RfalsepH determines the energetic efficiency of the cyanobacterial CO2 concentrating mechanism.Many carbon-fixing bacteria rely on a CO2 concentrating mechanism (CCM) to elevate the CO2 concentration around the carboxylating enzyme ribulose bisphosphate carboxylase/oxygenase (RuBisCO). The CCM is postulated to simultaneously enhance the rate of carboxylation and minimize oxygenation, a competitive reaction with O2 also catalyzed by RuBisCO. To achieve this effect, the CCM combines two features: active transport of inorganic carbon into the cell and colocalization of carbonic anhydrase and RuBisCO inside proteinaceous microcompartments called carboxysomes. Understanding the significance of the various CCM components requires reconciling biochemical intuition with a quantitative description of the system. To this end, we have developed a mathematical model of the CCM to analyze its en2016-01-01T00:00:00Z2016 Sep2026-05-05T17:29:44.994Z2019-03-27T02:23:56ZS-EPMC50187992755107910.1073/pnas.1525145113