5.1.1.4 evolution phylogenetic and syntenic data support a single horizontal transfer to a Trypanosoma ancestor of a prokaryotic proline racemase implicated in parasite evasion from host defences. TryPRAC homologues as single copy genes per haploid genome in 12 of 15 Trypanosoma species, including Trypanosoma cruzi and Trypanosoma cruzi marinkellei, Trypanosoma dionisii, Trypanosoma erneyi, Trypanosoma rangeli, Trypanosoma conorhini and Trypanosoma lewisi, all parasites of mammals. Polymorphisms in TcPRAC genes match Trypanosoma cruzi genotypes: TcI-TcIV and Tcbat have unique genes, while the hybrids TcV and TcVI contain TcPRACA and TcPRACB from parental TcII and TcIII, respectively. PRAC homologues are identified in trypanosomes from anurans, snakes, crocodiles, lizards, and birds. Most trypanosomes have intact PRAC genes. Trypanosoma rangeli possesses only pseudogenes, maybe in the process of being lost. Trypanosoma brucei, Trypanosoma congolense and their allied species, except the more distantly related Trypanosoma vivax, have completely lost PRAC genes. The genealogy of TryPRAC homologs supports an evolutionary history congruent with the Trypanosoma phylogeny -, 748829 5.1.1.4 evolution phylogenetic and syntenic data support a single horizontal transference to a Trypanosoma ancestor of a prokaryotic proline racemase implicated in parasite evasion from host defences. TryPRAC homologues as single copy genes per haploid genome in 12 of 15 Trypanosoma species, including Trypanosoma cruzi and Trypanosoma cruzi marinkellei, Trypanosoma dionisii, Trypanosoma erneyi, Trypanosoma rangeli, Trypanosoma conorhini and Trypanosoma lewisi, all parasites of mammals. Polymorphisms in TcPRAC genes match Trypanosoma cruzi genotypes: TcI-TcIV and Tcbat have unique genes, while the hybrids TcV and TcVI contain TcPRACA and TcPRACB from parental TcII and TcIII, respectively. PRAC homologues are identified in trypanosomes from anurans, snakes, crocodiles, lizards, and birds. Most trypanosomes have intact PRAC genes. Trypanosoma rangeli possesses only pseudogenes, maybe in the process of being lost. Trypanosoma brucei, Trypanosoma congolense and their allied species, except the more distantly related Trypanosoma vivax, have completely lost PRAC genes. The genealogy of TryPRAC homologs supports an evolutionary history congruent with the Trypanosoma phylogeny -, 748829 5.1.1.4 metabolism catalyzes step 8 in the ornithine fermentation pathway 704292 5.1.1.4 additional information the enzyme is a two-base racemase 727156 5.1.1.4 physiological function enzyme is a T-cell-independent B-cell mitogen, enzyme displays mitogenic activity towards splenic cells from euthymic Swiss mice, since addition of 0.1 mg/ml of recombinant protein promotes a 13fold increase of thymidine incorporation when compared with untreated cells, mitogenic activity of recombinant enzyme seems to be dependent on the active enzyme, since inhibition with 10 mM pyrrole-2-carboxylic acid prior to its incubation with splenocytes specifically decreases proliferation by 44%, enzyme triggers high levels of B-cell activation, terminal differentiation and antibody secretion 705596 5.1.1.4 physiological function inactivation of proline racemase PrdF by insertional mutagenesis does not affect early logarithmic growth but only attenuates growth in the mid- and late logarithmic phases. There is no effect of inactivation on virulence in vivo 727265 5.1.1.4 physiological function proline racemase is a T-cell-independent B-cell mitogen, stimulation of murine splenocytes with recombinant proline racemase C induces B-cell proliferation, antibody secretion, interleukin-10 production, and upregulation of CD69 and CD86 on B cells -, 715163 5.1.1.4 physiological function proline racemase is an effective mitogen for B cells, thus contributing to the parasites immune evasion and persistence in the human host 705499 5.1.1.4 physiological function proline racemase participates in mechanisms of virulence acquisition 705500