title: Higher-plant chloroplast and cytosolic fructose-1,6-bisphosphatase isoenzymes: origins via duplication rather than prokaryote-eukaryote divergence.
abstract: Full-size cDNAs encoding the precursors of chloroplast fructose-1,6-bisphosphatase (FBP), sedoheptulose-1,7-bisphosphatase (SBP), and the small subunit of Rubisco (RbcS) from spinach were cloned. These cDNAs complete the set of homologous probes for all nuclear-encoded enzymes of the Calvin cycle from spinach (Spinacia oleracea L.). FBP enzymes not only of higher plants but also of non-photosynthetic eukaryotes are found to be unexpectedly similar to eubacterial homologues, suggesting a eubacterial origin of these eukaryotic nuclear genes. Chloroplast and cytosolic FBP isoenzymes of higher plants arose through a gene duplication event which occurred early in eukaryotic evolution. Both FBP and SBP of higher plant chloroplasts have acquired substrate specificity, i.e. have undergone functional specialization since their divergence from bifunctional FBP/SBP enzymes of free-living eubacteria.
authors.affiliation: Institut für Genetik, Technische Universität Braunschweig, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Martin
authors.forename: A Z
authors.initials: AZ
authors.lastname: Mustafa
authors.forename: K
authors.initials: K
authors.lastname: Henze
authors.forename: C
authors.initials: C
authors.lastname: Schnarrenberger
mesh_terms: D000595:Amino Acid Sequence; D002736:Chloroplasts / Q000201:enzymology*; D003600:Cytosol / Q000201:enzymology*; D018076:DNA, Complementary / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D019143:Evolution, Molecular; D006597:Fructose-Bisphosphatase / Q000235:genetics*; D017343:Genes, Plant; D007527:Isoenzymes / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics; D010788:Photosynthesis / Q000235:genetics; D010802:Phylogeny; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D018724:Spinacia oleracea / Q000201:enzymology / Q000235:genetics; D013379:Substrate Specificity
chemical_list: D018076:DNA, Complementary; D018744:DNA, Plant; D007527:Isoenzymes; D006597:Fructose-Bisphosphatase; D010744:Phosphoric Monoester Hydrolases; C022627:sedoheptulose-bisphosphatase; D012273:Ribulose-Bisphosphate Carboxylase