TY - JOUR
T1 - Cellular and biochemical characterization of two closely related triosephosphate isomerases from Trichomonas vaginalis
AU - Figueroa-Angulo, Elisa E.
AU - Estrella-Hernández, Priscila
AU - Salgado-Lugo, Holjes
AU - Ochoa-Leyva, Adrián
AU - Puyou, Armando Gómez
AU - Campos, Silvia S.
AU - Montero-Moran, Gabriela
AU - Ortega-López, Jaime
AU - Saab-Rincón, Gloria
AU - Arroyo, Rossana
AU - Benítez-Cardoza, Claudia G.
AU - Brieba, Luis G.
PY - 2012/11
Y1 - 2012/11
N2 - 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 and encode ORFs of 254 amino acids; the only differences between them are the character of 4 amino acids located in α-helices 1, 2 and 8. Semi-quantitative RT-PCR assays showed that tpi2 transcript is approximately 3·3-fold more abundant than tpi1. Using an anti-TvTIM2 polyclonal antibody it was demonstrated that TIM proteins have a cytoplasmic localization and both enzymes are able to complement an Escherichia coli strain carrying a deletion of its endogenous tpi gene. Both TIM proteins assemble as dimers and their secondary structure assessment is essentially identical to TIM from Saccharomyces cerevisiae. The kinetic catalytic constants of the recombinant enzymes using glyceraldehyde-3-phosphate as substrate are similar to the catalytic constants of TIMs from other organisms including parasitic protozoa. As T. vaginalis depends on glycolysis for ATP production, we speculate 2 possible reasons to maintain a duplicated tpi copy on its genome: an increase in gene dosage or an early event of neofunctionalization of TIM as a moonlighting protein.
AB - 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 and encode ORFs of 254 amino acids; the only differences between them are the character of 4 amino acids located in α-helices 1, 2 and 8. Semi-quantitative RT-PCR assays showed that tpi2 transcript is approximately 3·3-fold more abundant than tpi1. Using an anti-TvTIM2 polyclonal antibody it was demonstrated that TIM proteins have a cytoplasmic localization and both enzymes are able to complement an Escherichia coli strain carrying a deletion of its endogenous tpi gene. Both TIM proteins assemble as dimers and their secondary structure assessment is essentially identical to TIM from Saccharomyces cerevisiae. The kinetic catalytic constants of the recombinant enzymes using glyceraldehyde-3-phosphate as substrate are similar to the catalytic constants of TIMs from other organisms including parasitic protozoa. As T. vaginalis depends on glycolysis for ATP production, we speculate 2 possible reasons to maintain a duplicated tpi copy on its genome: an increase in gene dosage or an early event of neofunctionalization of TIM as a moonlighting protein.
KW - amitocondriate protozoa
KW - central metabolism
KW - duplicated gene
KW - evolution
KW - structure-function
UR - http://www.scopus.com/inward/record.url?scp=84868294647&partnerID=8YFLogxK
U2 - 10.1017/S003118201200114X
DO - 10.1017/S003118201200114X
M3 - Artículo
SN - 0031-1820
VL - 139
SP - 1729
EP - 1738
JO - Parasitology
JF - Parasitology
IS - 13
ER -