Cellular and biochemical characterization of two closely related triosephosphate isomerases fromTrichomonas vaginalis

• DOI: 10.1017/s003118201200114x
• Publication Date: 2012-08-29T12:46:31Z
• Authors: ELISA E. FIGUEROA...; PRISCILA ESTRELLA...; HOLJES SALGADO-LUGO; ADRIÁN OCHOA-LEYVA; ARMANDO GÓMEZ PUYOU; SILVIA S. CAMPOS; GABRIELA MONTERO-...; JAIME ORTEGA-LÓPEZ; GLORIA SAAB-RINCÓN; ROSSANA ARROYO; CLAUDIA G. BENÍTE...; LUIS G. BRIEBA
• Keywords: Triosephosphate isomerase; Dihydroxyacetone phosphate; ORFS

SUMMARY The glycolytic enzyme triosephosphate isomerase catalyses the isomerization between glyceraldehyde 3-phosphate and dihydroxyacetone phosphate. Here we report that Trichomonas vaginalis contains 2 fully functional tpi genes. Both genes are located in separated chromosomal context with different promoter regulatory elements encode ORFs of 254 amino acids; only differences them character 4 acids α -helices 1, 8. Semi-quantitative RT-PCR assays showed tpi2 transcript is approximately 3·3-fold more abundant than tpi1 . Using an anti-TvTIM2 polyclonal antibody it was demonstrated TIM proteins have a cytoplasmic localization both enzymes able to complement Escherichia coli strain carrying deletion its endogenous gene. assemble as dimers their secondary structure assessment essentially identical from Saccharomyces cerevisiae kinetic catalytic constants recombinant using glyceraldehyde-3-phosphate substrate similar TIMs other organisms including parasitic protozoa. As T. depends on glycolysis for ATP production, speculate possible reasons maintain duplicated copy genome: increase gene dosage or early event neofunctionalization moonlighting protein.