The VIPER elements of trypanosomes constitute a novel group of tyrosine recombinase-enconding retrotransposons.

摘要: Abstract VIPER was initially characterized as a 2326 bp LTR-like retroelement associated to SIRE, short interspersed repetitive element specific of Trypanosoma cruzi . It carried single ORF that coded for putative reverse transcriptase-RNAse H protein, suggesting it could be truncated copy longer retroelement. Herein we report the identification and characterization complete 4480 bp long in T. genome. The harbored three non-overlapped domains encoding GAG-like, tyrosine recombinase proteins. elements were also found genomes brucei vivax , but not Leishmania sp On basis its transcriptase phylogeny, classified an LTR However, structurally related retroelements, DIRS Ngaro. Phylogenetic analysis showed VIPER's grouped with transposases RCI1 Escherichia coli Ye24 Ye72 Haemophilus influenzae within major branch prokaryotic recombinases. Taken together, structure, nature recombinase, unique features catalytic consensus motif fact Trypanosomes, early branching eukaryote, suggest may closest relative founder retrotransposons known up date. Our revealed recombinase-encoding retroelements originated evolution non-LTR suggests VIPER, Ngaro constitute third group retrotransposons, distinct from both retroelements.