title: Arginine kinase in Phytomonas, a trypanosomatid parasite of plants.
abstract: Phytomonas are trypanosomatid plant parasites closely related to parasites that cause several human diseases. Little is known about the biology of these organisms including aspects of their metabolism. Arginine kinase (E.C. 2.7.3.3) is a phosphotransferase which catalyzes the interconversion between the phosphagen phosphoarginine and ATP. This enzyme is present in some invertebrates and is a homolog of another widely distributed phosphosphagen kinase, creatine kinase. In this work, a single canonical arginine kinase isoform was detected in Phytomonas Jma by enzymatic activity assays, PCR, and Western Blot. This arginine kinase is very similar to the canonical isoforms found in T. cruzi and T. brucei, presenting about 70% of amino acid sequence identity and a very similar molecular weight (40kDa). The Phytomonas phosphagen system seems to be very similar to T. cruzi, which has only one isoform, or T. brucei (three isoforms); establishing a difference with other trypanosomatids, such as Leishmania, which completely lacks phosphagen kinases, probably by the presence of the arginine-consuming enzyme, arginase. Finally, phylogenetic analysis suggests that Kinetoplastids' arginine kinase was acquired, during evolution, from the arthropod vectors by horizontal gene transfer.
authors.affiliation: Laboratorio de Biología Molecular de Trypanosoma cruzi (LBMTC), Instituto de Investigaciones Médicas Alfredo Lanari, Universidad de Buenos Aires and CONICET, Buenos Aires, Argentina.
authors.forename: Gaspar E
authors.initials: GE
authors.lastname: Canepa
authors.forename: Carolina
authors.initials: C
authors.lastname: Carrillo
authors.forename: Mariana R
authors.initials: MR
authors.lastname: Miranda
authors.forename: Melisa
authors.initials: M
authors.lastname: Sayé
authors.forename: Claudio A
authors.initials: CA
authors.lastname: Pereira
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001122:Arginine Kinase / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D005075:Biological Evolution; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D010944:Plants / Q000469:parasitology*; D016415:Sequence Alignment; D014351:Trypanosomatina / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity*
chemical_list: D007527:Isoenzymes; D001122:Arginine Kinase