Integrative Control of Carbon, Nitrogen, Hydrogen, and Sulfur Metabolism: The Central Role of the Calvin–Benson–Bassham Cycle
Nonsulfur purple (NSP) photosynthetic bacteria use the Calvin–Benson– Bassham (CBB) reductive pentose phosphate pathway for the reduction of CO2 via ribulose 1,5-bisphosphate (RuBP) carboxylase–oxygenase (RubisCO), as a means to build cell mass during chemoautotrophic or photoautotrophic conditions. In addition, the CBB pathway plays an important role in maintaining redox balance during photoheterotrophic growth conditions. In this communication we describe protein– protein interactions between two transcriptional regulators CbbR and RegA and the possible role of the CbbX protein in regulating the CBB pathway in Rhodobacter sphaeroides. In Rhodopseudomonas palustris, the CbbR and the CbbRRS system (a three-protein, two-component regulatory system) regulate the CBB pathway. Moreover, derepression of the nitrogenase complex, and the production of hydrogen gas, appears to be a common mechanism to balance the redox potential in RubisCO-compromised strains of NSP photosynthetic bacteria.
KeywordsRhodobacter Sphaeroides Rhodopseudomonas Palustris Photoautotrophic Growth Photoheterotrophic Growth Phosphoglycolate Phosphatase
This work was supported by grants DE-FG02-07ER64489 and DE-FG02- DE-FG02-08ER15976 from the Office of Biological and Environmental Research (Genomics: GTL Program) and the Chemical Sciences, Geosciences, and Biosciences Division of the Office of Basic Energy Sciences, respectively, of the US Department of Energy
- Anderson L, Fuller RC (1967a) Photosynthesis in Rhodospirillum rubrum II. Photoheterotrophic carbon dioxide fixation. Plant Physiol 42:491–496Google Scholar
- Anderson L, Fuller RC (1967b) Photosynthesis in Rhodospirillum rubrum I. Autotrophic carbon dioxide fixation. Plant Physiol 42:487–490Google Scholar
- Romagnoli S, Tabita FR (2009) Carbon dioxide metabolism and its regulation in nonsulfur purple photosynthetic bacteria. In: Hunter CN, Daldal F, Thurnauer MC, Beatty JT (eds) The purple phototrophic bacteria. Advances in photosynthesis and respiration, vol. 28. Springer, Dordrecht, pp 563–576Google Scholar