title: Glutamate synthase is plastid-encoded in a red alga: implications for the evolution of glutamate synthases.
abstract: An actively transcribed gene (glsF) encoding for ferredoxin-dependent glutamate synthase (Fd-GOGAT) was found on the plastid genome of the multicellular red alga Antithamnion sp. Fd-GOGAT is not plastid-encoded in chlorophytic plants, demonstrating that red algal plastid genomes encode for additional functions when compared to those known from green chloroplasts. Moreover, our results suggest that the plant Fd-GOGAT has an endosymbiotic origin. The same may not be true for NADPH-dependent GOGAT. In Antithamnion glsF is flanked upstream by cpcBA and downstream by psaC and is transcribed monocistronically. Implications of these results for the evolution of GOGAT enzymes and the plastid genome are discussed.
authors.affiliation: Institute for Plant Physiology, Giessen, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Valentin
authors.forename: M
authors.initials: M
authors.lastname: Kostrzewa
authors.forename: K
authors.initials: K
authors.lastname: Zetsche
mesh_terms: D000595:Amino Acid Sequence; D005075:Biological Evolution; D015152:Blotting, Northern; D015139:Blotting, Southern; D003001:Cloning, Molecular; D005970:Glutamate Synthase / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D018087:Plastids / Q000201:enzymology*; D000461:Rhodophyta / Q000201:enzymology / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
chemical_list: D005970:Glutamate Synthase