Characterization of the VIPER?s retroelement family of T. cruzi genome

ROBLEDO, GERMÁN; ROCHA, CRISTIAN; LORENZI, HERNAN A.; VAZQUEZ, MARTIN; LEVIN, MARIANO J.

Congreso; XXXIX Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB); 2003

Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB).

The Vestigial IntersPersEd Retroelement, VIPER, is a retrotransposon of Trypanosoma cruzi. This is 2,359 bp long fragment that has been isolated from the λZapII genomic library. VIPER?s 5´ and 3´ end consist of the first 182 bp and last 226 bp of SIRE (Short Interspersed Repetitive Element) respectively. Both SIRE?s moieties are connected by a 1,924 bp long fragment that carries a unique ORF encoding reverse transcriptase and RNase H motive. The last 15 C-terminal amino acids derive from codons specified by SIRE?s moiety 3?. The amino acid sequence of this protein share significant homology with the RT-RNAse H genes of differents retroelements. By performing public databases searching, new VIPER-like elements were found, with similar structure and an approximately size of 4 kb. From these sequences a longer ORF was deduced, that also confirm the RT and RNAsa H motifs described for VIPER. A CCHC motif can be use to define a probable reading frame for a gag protein. One of these new elements were found on a 123kb. fragment of the T. cruzi chromosome 3 that is syntenyc with genomic regions of T. brucei chromosme 1 and L. major chromosome 12. Analysis of the RT-RNAse H motifs and the insertion sites of these elements led to the confirmation of its definition as a LTR-like retrotransposon, different to the non?LTR described for T. cruzi up to date.