Structural features of mag, a gypsy-like retrotransposon ofBombyx mori, with unusual short terminal repeats

Publisher Website
Google Scholar
Abstract
Mag is a retrotransposon found as an insert in the Sericin 2 gene. It is present in a few copies −4 to 15-dispersed in the genome of different strains ofBombyx mori as well as inBombyx mandarina. Flanked by a 5 bp target sequence with no sequence specificity, it is bordered by direct repeats of 77 nucleotides. Despite their unusual short size, these terminal repeats and their immediately adjacent sequences present all the signals necessary for transcription into genomic RNA and for reverse transcription. Mag contains two overlapping open reading frames which are organized as thegag andpol genes of retroviruses and encode putative nucleic acid binding peptide, protease, reverse transcriptase, RNase H and endonuclease in this order. Sequence comparison of these proteins places mag within the gypsy group of LTR retrotransposons next to the echinoderm element SURL.