Figure 4

Schematic representation of the structure of non-LTR retrotransposons of the RTE and CR1 clades, including RTE-1 from Caenorhabditis elegans, SR2 and SR3 from Schistosoma mansoni, CR1 from Gallus gallus, and Perere-5, and SR1-like retrotransposon from S. mansoni. (The structure of a full-length copy of SR1 has not been reported [15, 22].) The sequence motifs of the 3'-termini are shown, along with positions of enzymatic domains, EN (endonuclease) and RT (reverse transcriptase). The RTE-1 element (3291 bp) illustrated here includes the 3'-UTR so that it is longer than the 3258 bp, described in Malik and Eickbush [17] (which included only the region between the 5'-end and the termination codon).