A RuBisCO-mediated carbon metabolic pathway in methanogenic archaea
Citations Over TimeTop 10% of 2017 papers
Abstract
Two enzymes are considered to be unique to the photosynthetic Calvin-Benson cycle: ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), responsible for CO2 fixation, and phosphoribulokinase (PRK). Some archaea possess bona fide RuBisCOs, despite not being photosynthetic organisms, but are thought to lack PRK. Here we demonstrate the existence in methanogenic archaea of a carbon metabolic pathway involving RuBisCO and PRK, which we term 'reductive hexulose-phosphate' (RHP) pathway. These archaea possess both RuBisCO and a catalytically active PRK whose crystal structure resembles that of photosynthetic bacterial PRK. Capillary electrophoresis-mass spectrometric analysis of metabolites reveals that the RHP pathway, which differs from the Calvin-Benson cycle only in a few steps, is active in vivo. Our work highlights evolutionary and functional links between RuBisCO-mediated carbon metabolic pathways in methanogenic archaea and photosynthetic organisms. Whether the RHP pathway allows for autotrophy (that is, growth exclusively with CO2 as carbon source) remains unknown.
Related Papers
- → Effect of salinity on the synthesis of ribulose-1,5-bisphosphate carboxylase/oxygenase in barley leaves(1992)81 cited
- → In situ assay of ribulose-1,5-bisphosphate carboxylase/oxygenase in Thiobacillus neapolitanus(1991)20 cited
- → Occurence and regulation of Calvin cycle enzymes in non-autotrophic Beggiatoa strains(1988)20 cited
- → Activation of Rubisco controls CO2 assimilation in light: a perspective on its discovery(2004)13 cited
- → Ribulose Bisphosphate-Induced, Slow Conformational Changes of Spinach Ribulose Bisphosphate Carboxylase Cause the Two Types of Inflections in the Course of Its Carboxylase Reaction1(1991)23 cited