Gabel is a LTR retrotransposon found in three-spined stickleback fish Gasterosteus aculeatus (Llorens et al. 2009). Its name is an acronym derived from “Gasterosteus aculeatus Bel/Pao element”. Gabel belongs to the Suzu clade (Copeland et al. 2005) within Branch 2 of the Bel/Pao family (Llorens et al. 2009).
Its genome is 7255 bp long, including LTRs of 440 nt. The internal region of this element contains three ORFs encoding for the gag and pol polyproteins. The largest ORF of 1254 amino acids (aa) displays the three gag domains (MA, CA, and NC) and the protease and reverse transcriptase domains. The second (262 aa) and the third (398 aa) ORFs code respectively for the putative RNase H and integrase pol proteins (Llorens et al. 2009).
Figure not to scale. If present, long terminal repeats (LTRs) have been highlighted in blue. Amino acid motifs noted with lines indicate the conserved residues in each protein domain, abbreviations below mean:
||DU or DUT=dUTPase
||TAV or IBMP=transactivator/viroplasmin or inclusion body matrix protein
||PBS=primer binding site
||ATF=aphid transmission factor
||VAP=virion associated protein