Mag is a LTR retrotransposon characterized in the genome of Bombyx mori (Michaille et al. 1990). Mag gives the name and belongs, along with other LTR retrotransposons, to Mag a large Ty3/Gypsy cluster widely distributed in both protostomes and deuterostomes (for more details, see Malik and Eickbush 1999; Volff et al. 2001; Tubio, Naveira and Costas 2004). The genomic structure of Mag is 4.6Kb in size including LTRs of 77 nt. The internal region of this element displays a Primer Binding Site (PBS) complementary to a tRNASer, two Open Reading Frames (ORFs) for gag, and pol genes, and a Polypurine Tract (PPT) adjacent to the 3' LTR (Michaille et al. 1990).
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
Mobile DNA II. (Craig et al. 2002)