Max is a LTR retrotransposon described in the genome of the dipter Drosophila melanogater (Marsano et al. 2004). Max belongs to Bel clade (Copeland et al. 2005) within Branch 1 of the Bel/Pao family (Llorens et al. 2009). The genome of Max is 8.8 Kb in size (8832 bp in lenght), including LTRs of 321 nt. The internal region of this LTR retrotransposon displays a Primer Binding Site (PBS), complementary to a tRNATyr, two ORFs of 1830- and 292-amino acids respectively, and a polypurine tract (PPT) immediately upstream of its 3’ LTR. The largest ORF encodes for both gag and pol polyproteins, our similarity analyses suggest that the smaller ORF is an extra gag-protease domain. Finally, upstream to the coding region the genome of Max shows several direct and inverted short repeats (Marsano et al. 2004).
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