title: Plastidic aspartate aminotransferases and the biosynthesis of essential amino acids in plants.
abstract: In the chloroplasts and in non-green plastids of plants, aspartate is the precursor for the biosynthesis of different amino acids and derived metabolites that play distinct and important roles in plant growth, reproduction, development or defence. Aspartate biosynthesis is mediated by the enzyme aspartate aminotransferase (EC 2.6.1.1), which catalyses the reversible transamination between glutamate and oxaloacetate to generate aspartate and 2-oxoglutarate. Plastids contain two aspartate aminotransferases: a eukaryotic-type and a prokaryotic-type bifunctional enzyme displaying aspartate and prephenate aminotransferase activities. A general overview of the biochemistry, regulation, functional significance, and phylogenetic origin of both enzymes is presented. The roles of these plastidic aminotransferases in the biosynthesis of essential amino acids are discussed.
authors.affiliation: Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus Universitario de Teatinos, 29071 Málaga, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: de la Torre
authors.affiliation: Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus Universitario de Teatinos, 29071 Málaga, Spain.
authors.forename: Rafael A
authors.initials: RA
authors.lastname: Cañas
authors.affiliation: Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus Universitario de Teatinos, 29071 Málaga, Spain.
authors.forename: M Belén
authors.initials: MB
authors.lastname: Pascual
authors.affiliation: Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus Universitario de Teatinos, 29071 Málaga, Spain.
authors.forename: Concepción
authors.initials: C
authors.lastname: Avila
authors.affiliation: Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus Universitario de Teatinos, 29071 Málaga, Spain canovas@uma.es.
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Cánovas
mesh_terms: D000601:Amino Acids, Essential / Q000378:metabolism*; D001219:Aspartate Aminotransferases / Q000235:genetics / Q000378:metabolism*; D001224:Aspartic Acid / Q000378:metabolism; D002736:Chloroplasts / Q000201:enzymology; D018698:Glutamic Acid / Q000378:metabolism; D007656:Ketoglutaric Acids / Q000378:metabolism; D008954:Models, Biological; D062907:Oxaloacetic Acid / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D010944:Plants / Q000201:enzymology*; D018087:Plastids / Q000201:enzymology; D013379:Substrate Specificity; D014443:Tyrosine / Q000378:metabolism
chemical_list: D000601:Amino Acids, Essential; D007656:Ketoglutaric Acids; D010940:Plant Proteins; D062907:Oxaloacetic Acid; D001224:Aspartic Acid; D018698:Glutamic Acid; D014443:Tyrosine; D001219:Aspartate Aminotransferases
keywords: Arogenate; aromatic amino acids; aspartate; aspartate metabolic pathway; plastid; prephenate.