Cloning of a pyruvate phosphate dikinase from Trypanosoma cruzi.
We have cloned and characterised a gene that encodes a putative pyruvate phosphate dikinase (PPDK) from Trypanosoma cruzi, an enzyme that catalyses the reversible conversion of phosphoenolpyruvate to pyruvate. PPDK is absent in mammalian cells, but has been found in a wide variety of other organisms, including plants and bacteria. In T. cruzi, two genes (PPDK1 and PPDK2) are present in a tandem array localised on a 1 Mbp chromosome. Northern and Western blot analyses indicates that PPDK is expressed as a 100-kDa protein in epimastigote, amastigote and trypomastigote forms. PPDK1 and PPDK2 encode an identical protein of 100.8 kDa with a C-terminal extension ending with the sequence AKL, a signal for glycosomal import. Both T. cruzi and T. brucei enzymes possess a 23-residue insertion, that is absent in other PPDKs. A three-dimensional alignment with the crystal structure of the enzyme from Clostridium symbiosum predicts that this insertion is located on the surface of the nucleotide-binding domain. Phylogenetic studies indicate that bacterial and protist PPDKs cluster as a separate group from those of plants. The evolutionary implications and possible role of this enzyme in T. cruzi is discussed.
Maldonado
R A
RA
Division of Biological Chemistry and Molecular Microbiology, School of Life Sciences, Wellcome Trust Biocentre, University of Dundee, Dundee DD1 5EH, UK.
Fairlamb
A H
AH
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D015139:Blotting, Southern; D015153:Blotting, Western; D020134:Catalytic Domain; D003001:Cloning, Molecular; D018507:Gene Expression Regulation, Developmental; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D011772:Pyruvate, Orthophosphate Dikinase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D014349:Trypanosoma cruzi / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development
D012333:RNA, Messenger; D011772:Pyruvate, Orthophosphate Dikinase