Article thumbnail

Rubisco mutagenesis provides new insight into limitations on photosynthesis and growth in Synechocystis PCC6803

By Yehouda Marcus, Hagit Altman-Gueta, Yael Wolff and Michael Gurevitz


Orthophosphate (Pi) stimulates the activation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) while paradoxically inhibiting its catalysis. Of three Pi-binding sites, the roles of the 5P- and latch sites have been documented, whereas that of the 1P-site remained unclear. Conserved residues at the 1P-site of Rubisco from the cyanobacterium Synechocystis PCC6803 were substituted and the kinetic properties of the enzyme derivatives and effects on cell photosynthesis and growth were examined. While Pi-stimulated Rubisco activation diminished for enzyme mutants T65A/S and G404A, inhibition of catalysis by Pi remained unchanged. Together with previous studies, the results suggest that all three Pi-binding sites are involved in stimulation of Rubisco activation, whereas only the 5P-site is involved in inhibition of catalysis. While all the mutations reduced the catalytic turnover of Rubisco (Kcat) between 6- and 20-fold, the photosynthesis and growth rates under saturating irradiance and inorganic carbon (Ci) concentrations were only reduced 40–50% (in the T65A/S mutants) or not at all (G404A mutant). Analysis of the mutant cells revealed a 3-fold increase in Rubisco content that partially compensated for the reduced Kcat so that the carboxylation rate per chlorophyll was one-third of that in the wild type. Correlation between the kinetic properties of Rubisco and the photosynthetic rate (Pmax) under saturating irradiance and Ci concentrations indicate that a >60% reduction in Kcat can be tolerated before Pmax in Synechocystsis PCC6803 is affected. These results indicate that the limitation of Rubisco activity on the rate of photosynthesis in Synechocystis is low. Determination of Calvin cycle metabolites revealed that unlike in higher plants, cyanobacterial photosynthesis is constrained by phosphoglycerate reduction probably due to limitation of ATP or NADPH

Topics: Research Papers
Publisher: Oxford University Press
OAI identifier:
Provided by: PubMed Central

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.

Suggested articles


  1. (1980). A biochemical model of photosynthetic CO2 fixation in leaves of C3 species.
  2. (2000). Activation of cyanobacterial RuBPcarboxylase/oxygenase is facilitated by inorganic phosphate via two independent mechanisms.
  3. (2006). Alterations in Rubisco activity and in stomatal behavior induce a daily rhythm in photosynthesis of aerial leaves in the amphibious plant. Nuphar lutea.
  4. (1989). Amplified expression of ribulose bisphosphate carboxylase/oxygenase in pBR322-transformants of. Anacystis nidulans.
  5. (1996). Antisense RNA inhibition of rbcS gene expression reduces rubisco level and photosynthesis in the C4 plant. Flaveria bidentis.
  6. (1986). Assimilatory power as a driving force in photosynthesis.
  7. (1958). Assimilatory power in photosynthesis: photosynthetic phosphorylation by isolated chloroplasts is coupled with TPN reduction.
  8. (1979). Carbon dioxide assimilation in cyanobacteria: regulation of ribulose 1,5-bisphospate carboxylase.
  9. (1974). Chemical and biological evolution of a nucleotide binding protein.
  10. (1993). Construction of Synechocystis PCC6803 mutant suitable for the study of variant hexadecameric ribulose bisphospate carboxylase/oxygenase enzymes.
  11. (2005). ConSurf 2005: the projection of evolutionary Novel constraints of cyanobacterial photosynthesis | 4181conservation scores of residues on protein structures.
  12. (2010). Cross-species analysis traces adaptation of Rubisco toward optimality in a low-dimensional landscape.
  13. (1990). Crystallographic analysis of ribulose-1,5-bisphosphate carboxylase from spinach at 2.4 A ˚ resolution.
  14. (1991). Decreased ribulose-1,5-bisphosphate carboxylaseoxygenase in transgenic tobacco transformed with ‘antisense’ rbcS: II. Flux-control coefficients for photosynthesis in varying light, CO2, and air humidity.
  15. (2003). Dual role of Cysteine 172 in redox regulation of ribulose 1,5-bisphosphate Carboxylase/Oxygenase activity and degradation.
  16. (1987). Energization and activation of inorganic carbon uptake by light in cyanobacteria.
  17. (1988). Enzymatic regulation of photosynthetic CO2 fixation in C3 plants.
  18. (1975). Enzyme kinetics.
  19. (1990). Enzymes of the Calvin cycle.
  20. (2006). Expression of foreign type I ribulose-1,5-bisphosphate carboxylase/oxygenase (EC stimulates photosynthesis in cyanobacterium Synechococcus PCC7942 cells.
  21. (1969). Free energy changes and metabolic regulation in steady-state photosynthetic carbon reduction.
  22. (1997). Gapped BLAST and PSI-BLAST: a new generation of protein database search programs.
  23. (1998). Mechanism of Rubisco: the carbamate as general base.
  24. (1974). Methods of enzymatic analysis.
  25. (2005). Mutagenesis at two distinct phosphate-binding sites unravels their differential roles in regulation of Rubisco activation and catalysis.
  26. (1994). Mutations of an active site threonyl residue promote b-elimination and other side reactions of the enediol intermediate of the ribulosebisphosphate carboxylase reaction.
  27. (1981). On the mechanism of the effector mediated activation of ribulose bisphosphate carboxylase/oxygenase.
  28. (1978). Phosphate requirement for the light activation of ribulose-1,5-bisphosphate carboxylase in intact spinach chloroplasts.
  29. (1992). Photosynthesis and photorespiration in a mutant of the cyanobacterium Synechocystis PCC6803 lacking carboxysomes.
  30. (1980). Photosynthesis and the intracellular inorganic carbon pool in the blue green alga Anabaena variabilis: response to external CO2 concentration.
  31. (1984). Rate-limiting factors in leaf photosynthesis. I. Carbon fluxes in the Calvin cycle.
  32. (1995). Regulation of ribulose 1,5-bisphosphate carboxylase/oxygenase activation by inorganic phosphate through stimulating the binding of the activator CO2 to the activation sites.
  33. (1985). Stimulation of ribulose bisphosphate carboxylase by inorganic orthophosphate without an increase in bound-activating CO2: cooperativity between the subunits of the enzyme.
  34. (1999). Structural motif of phosphate-binding site common to various protein superfamilies: allagainst-all structural comparison of protein–mononucleotide complexes.
  35. (1996). Structural transitions during activation and ligand binding in hexadecameric Rubisco inferred from the crystal structure of the activated unliganded spinach enzyme.
  36. (2003). The Calvin cycle revisited.
  37. (1984). The carboxysomes (polyhedral bodies) of autotrophic prokaryotes.
  38. (1973). The control of flux.
  39. (2006). The environmental plasticity and ecological genomics of the cyanobacterial CO2 concentrating mechanism.
  40. (1997). The structure and function of Rubisco and their implications for systematic studies.
  41. (2000). The transition between the open and closed states of rubisco is triggered by the interphosphate distance of the bound bisphosphate.