New roads lead to Rubisco in archaebacteria.
The discovery of the CO(2)-fixing enzyme Rubisco in the Archaebacteria has presented a conundrum in that they apparently lack the gene for phosphoribulokinase, which is required to generate Rubisco's substrate ribulose 1,5-bisphosphate (RuBP). However, two groups have now demonstrated novel RuBP synthesis pathways, demystifying Rubisco's non-autotrophic and perhaps ancient role. A new CO(2) fixing role for Rubisco, which is distinct from the globally dominant Calvin cycle, is providing important clues furthering our understanding of the evolution of autotrophy. This perspective is strengthened by the additional recognition in this commentary that some Rubisco-containing Archaea do also contain PRK and may represent an interesting autotrophic evolutionary transition. Supplementary material for this article can be found on the BioEssays website (http://www.interscience.wiley.com/jpages/0265-9247/suppmat/index.html).
Mueller-Cajar
Oliver
O
Molecular Plant Physiology Group, Research School of Biological Sciences, Australian National University, Canberra, ACT 2601, Australia.
Badger
Murray Ronald
MR
D001105:Archaea / Q000201:enzymology* / Q000235:genetics; D019143:Evolution, Molecular; D008954:Models, Biological; D010788:Photosynthesis / Q000235:genetics; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics / Q000502:physiology*; D012689:Sequence Homology, Nucleic Acid
D012273:Ribulose-Bisphosphate Carboxylase