Suck G, Traut W
Institut für Biologie, Medizinische Universität zu Lübeck, D-23538, Lübeck, Germany.
Gene. 2000 Sep 5;255(1):51-7. doi: 10.1016/s0378-1119(00)00311-5.
We describe TROMB, a new LTR retrotransposon, from the phorid fly Megaselia scalaris. Three full-length copies (4226, 4160 and 4129bp) and a truncated one (319bp) have been isolated. The target site consensus is TATAT, with a 4bp target site duplication TATA. The LTRs are short (142bp) and contain a TATA-box and a polyadenylation signal. The isolated copies are degenerate to different degrees and presumably inactive. The polyprotein coding sequence contains scattered stop codons and deletions/insertions at non-homologous positions. The consensus sequence among the three full-length copies, however, has an uninterrupted open reading frame and, presumably, represents the original sequence of the active element. Southern hybridization experiments showed TROMB to be present at a low copy number in two wild-type strains of M. scalaris and absent in a related species, M. abdita. The order of domains in the polyprotein coding region, the target site specificity for AT-rich sequences, and the protein sequence similarity to blastopia, mdg3 and micropia place TROMB in the gypsy-Ty3 group of LTR retrotransposons.
我们描述了来自蚤蝇（Megaselia scalaris）的一种新型LTR逆转录转座子TROMB。已分离出三个全长拷贝（4226、4160和4129bp）和一个截短的拷贝（319bp）。靶位点共有序列为TATAT，伴有4bp的靶位点重复TATA。LTR较短（142bp），包含一个TATA盒和一个聚腺苷酸化信号。分离出的拷贝存在不同程度的退化，推测无活性。多蛋白编码序列包含分散的终止密码子以及非同源位置的缺失/插入。然而，三个全长拷贝之间的共有序列具有不间断的开放阅读框，推测代表了活性元件的原始序列。Southern杂交实验表明，TROMB在蚤蝇的两个野生型菌株中以低拷贝数存在，而在相关物种M. abdita中不存在。多蛋白编码区结构域的顺序、对富含AT序列的靶位点特异性以及与blastopia、mdg3和micropia的蛋白质序列相似性，将TROMB置于LTR逆转录转座子的gypsy - Ty3组中。
