title: Evolution of enzymes involved in the photorespiratory 2-phosphoglycolate cycle from cyanobacteria via algae toward plants.
abstract: The photorespiratory pathway was shown to be essential for organisms performing oxygenic photosynthesis, cyanobacteria, algae, and plants, in the present day O(2)-containing atmosphere. The identification of a plant-like 2-phosphoglycolate cycle in cyanobacteria indicated that not only genes of oxygenic photosynthesis but also genes encoding photorespiratory enzymes were endosymbiotically conveyed from ancient cyanobacteria to eukaryotic oxygenic phototrophs. Here, we investigated the origin of the photorespiratory pathway in photosynthetic eukaryotes by phylogenetic analysis. We found that a mixture of photorespiratory enzymes of either cyanobacterial or α-proteobacterial origin is present in algae and higher plants. Three enzymes in eukaryotic phototrophs clustered closely with cyanobacterial homologs: glycolate oxidase, glycerate kinase, and hydroxypyruvate reductase. On the other hand, the mitochondrial enzymes of the photorespiratory cycle in algae and plants, glycine decarboxylase subunits and serine hydroxymethyltransferase, evolved from proteobacteria. Other than most genes for proteins of the photosynthetic machinery, nearly all enzymes involved in the 2-phosphogylcolate metabolism coexist in the genomes of cyanobacteria and heterotrophic bacteria.
authors.affiliation: Universität Rostock, Institut für Biowissenschaften, Abteilung Pflanzenphysiologie, Rostock, Germany.
authors.forename: Ramona
authors.initials: R
authors.lastname: Kern
authors.forename: Hermann
authors.initials: H
authors.lastname: Bauwe
authors.forename: Martin
authors.initials: M
authors.lastname: Hagemann
mesh_terms: D000429:Alcohol Oxidoreductases / Q000235:genetics; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D005075:Biological Evolution; D019069:Cell Respiration; D002736:Chloroplasts / Q000235:genetics; D000458:Cyanobacteria / Q000201:enzymology / Q000235:genetics*; D050841:Glycine Dehydrogenase (Decarboxylating) / Q000235:genetics; D012696:Glycine Hydroxymethyltransferase / Q000235:genetics; D006016:Glycolates / Q000378:metabolism*; D050537:Hydroxypyruvate Reductase / Q000235:genetics; D008928:Mitochondria / Q000235:genetics; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics; D010788:Photosynthesis; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics; D010944:Plants / Q000201:enzymology / Q000235:genetics*; D020560:Proteobacteria / Q000201:enzymology / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D006016:Glycolates; D010940:Plant Proteins; D000429:Alcohol Oxidoreductases; D050537:Hydroxypyruvate Reductase; C020821:glycollate oxidase; D050841:Glycine Dehydrogenase (Decarboxylating); D012696:Glycine Hydroxymethyltransferase; D017853:Phosphotransferases (Alcohol Group Acceptor); C020670:glycerate kinase; C013193:phosphoglycolate