title: Cloning, expression and biochemical characterization of mitochondrial and cytosolic malate dehydrogenase from Phytophthora infestans.
abstract: The genes of the mitochondrial and cytosolic malate dehydrogenase (mMDH and cMDH) of Phytophthora infestans were cloned and overexpressed in Escherichia coli as active enzymes. The catalytic properties of these proteins were determined: both enzymes have a similar specific activity. In addition, the natural mitochondrial isoenzyme was semi-purified from mycelia and its catalytic properties determined: the recombinant mitochondrial isoform behaved as the natural enzyme. A phylogenetic analysis indicated that mMDH, present in all stramenopiles studied, can be useful to study the relationships between these organisms. MDH with the conserved domain MDH_cytoplasmic_cytosolic is absent in some stramenopiles as well as in fungi. This enzyme seems to be less related within the stramenopile group. The Phytophthora cMDHs have an insertion of six amino acids that is also present in the stramenopile cMDHs studied, with the exception of Thalassiosira pseudonana cMDH, and is absent in other known eukaryotic cMDHs.
authors.affiliation: Laboratorio de Fisiología, Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela.
authors.forename: Patricia E
authors.initials: PE
authors.lastname: López-Calcagno
authors.forename: Johanna
authors.initials: J
authors.lastname: Moreno
authors.forename: Luis
authors.initials: L
authors.lastname: Cedeño
authors.forename: Luis
authors.initials: L
authors.lastname: Labrador
authors.forename: Juan L
authors.initials: JL
authors.lastname: Concepción
authors.forename: Luisana
authors.initials: L
authors.lastname: Avilán
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D003600:Cytosol / Q000737:chemistry / Q000201:enzymology*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D007700:Kinetics; D008291:Malate Dehydrogenase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D009868:Oomycetes / Q000737:chemistry / Q000145:classification / Q000235:genetics; D010802:Phylogeny; D055750:Phytophthora infestans / Q000737:chemistry / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D016415:Sequence Alignment
chemical_list: D008291:Malate Dehydrogenase