RuBisCO
Ribulose-1,5-bisphosphate carboxylase oxygenase, better known as RuBisCO,[note 1] is an enzyme that catalyzes the first major step of carbon fixation in the Calvin cycle. Carbon fixation is how the atoms of atmospheric carbon dioxide are made available to organisms in the form of energy-rich molecules such as glucose. RuBisCO splits 6-C molecules into two equal parts.
RuBisCO is very important in biology and ecology because it catalyzes the primary chemical reaction by which inorganic carbon permanently enters the biosphere.
RuBisCO is also the most abundant protein in leaves and the most abundant protein on Earth.[3][4][5] It accounts for 50% of soluble leaf protein (20-30% of total leaf nitrogen) and 30% of soluble leaf protein in plants (5-9% of total leaf nitrogen).[5]
Given its important role in the biosphere, there are currently efforts to genetically engineer crop plants to contain more efficient RuBisCO.[6]
Notes and references
- Notes
- References
RuBisCO Media
Location of the rbcL gene in the chloroplast genome of Arabidopsis thaliana (positions ca. 55-56.4 kb). rbcL is one of the 21 protein-coding genes involved in photosynthesis (green boxes).
Two main reactions of RuBisCo: CO2 fixation and oxygenation.
A 3D image of the active site of spinach RuBisCO complexed with the inhibitor 2-carboxyarabinitol-1,5-bisphosphate, CO2, and Mg2+. (PDB: 1IR1; Ligand View [CAP]501:A)
Overview of the Calvin cycle and carbon fixation.
Figure 3. In this figure, each protein chain in the (LS)2 complex is given its own color for easy identification.
- ↑ Wildman SG. Along the trail from fraction I protein to Rubisco (ribulose bisphosphate carboxylase-oxygenase). Photosyn. Res. 73 (1–3) (2002). p. 243–50. doi:10.1023/A:1020467601966.
- ↑ Portis AR, Parry MA. Discoveries in Rubisco (Ribulose 1,5-bisphosphate carboxylase/oxygenase): a historical perspective. Photosyn. Res. 94 (1) (October 2007). p. 121–43. doi:10.1007/s11120-007-9225-6.
- ↑ Cooper, Geoffrey M.. The Cell: a molecular approach (2000). Washington, D.C: ASM Press. ISBN 0-87893-106-6.
- ↑ Dhingra A, Portis AR, Daniell H. Enhanced translation of a chloroplast-expressed RbcS gene restores small subunit levels and photosynthesis in nuclear RbcS antisense plants. Proc. Natl. Acad. Sci. U.S.A. 101 (16) (April 2004). p. 6315–20. doi:10.1073/pnas.0400981101.
- ↑ 5.0 5.1 Feller U, Anders I, Mae T. Rubiscolytics: fate of Rubisco after its enzymatic function in a cell is terminated. J. Exp. Bot. 59 (7) (2008). p. 1615–24. doi:10.1093/jxb/erm242.
- ↑ Ellis, R. John 2010. Biochemistry: tackling unintelligent design. Nature 463, 164-165 doi:10.1038/463164a [1]