Month Flat Week Day
Thursday, October 25, 2012 14:00 - 15:00
1 Hour
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Contact info
Christiane Funk

Martin Hagemann
Universität Rostock, Institut für Biowissenschaften, Abteilung Pflanzenphysiologie

Evolutionary origin of photorespiration: Phylogenetic and biochemical studies of enzymes involved in the 2-phosphoglycolate metabolism

Place: Lilla hörsalen, KB3A9

Abtract:The photorespiratory pathway is essential for organisms performing oxygenic photosynthesis, cyanobacteria, algae and plants, in the present day O2-containing atmosphere. The presence 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. BlastP analyses with plant photorespiratory proteins identified several proteins in cyanobacteria and algae with surprisingly high sequence similarities. To verify that not only the sequence but also the biochemical activity of these enzymes is conserved, selected proteins from the cyanobacteria Synechocystis PCC 6803, Anabaena PCC 7120 and Cyanothece sp. PCC 7822, as well as from the algae Chlamydomonas reinhardtii and Cyanidioschyzon merolae were overexpressed in E. coli and biochemical analyzed. As examples, data will be presented on our recent analyses of glycolate oxidases and hydroxypyruvate reductase, which allowed to date the origin of photorespiration back to the protoalgae