Fanning T, Singer M
Nucleic Acids Res. 1987 Mar 11;15(5):2251-60. doi: 10.1093/nar/15.5.2251.
Recent work suggests that one or more members of the highly repeated LINE-1 (L1) DNA family found in all mammals may encode one or more proteins. Here we report the sequence of a portion of an L1 cloned from the domestic cat (Felis catus). These data permit comparison of the L1 sequences in four mammalian orders (Carnivore, Lagomorph, Rodent and Primate) and the comparison supports the suggested coding potential. In two separate, noncontiguous regions in the carboxy terminal half of the proteins predicted from the DNA sequences, there are several strongly conserved segments. In one region, these share homology with known or suspected reverse transcriptases, as described by others in rodents and primates. In the second region, closer to the carboxy terminus, the strongly conserved segments are over 90% homologous among the four orders. One of the latter segments is cysteine rich and resembles the putative metal binding domains of nucleic acid binding proteins, including those of TFIIIA and retroviruses.
最近的研究表明，在所有哺乳动物中发现的高度重复的LINE-1（L1）DNA家族中的一个或多个成员可能编码一种或多种蛋白质。在此，我们报告了从家猫（Felis catus）克隆的一段L1的序列。这些数据允许对四个哺乳动物目（食肉目、兔形目、啮齿目和灵长目）中的L1序列进行比较，并且该比较支持了所提出的编码潜力。在从DNA序列预测的蛋白质的羧基末端一半的两个不连续的区域中，有几个高度保守的片段。在一个区域中，这些片段与已知或疑似逆转录酶具有同源性，正如其他研究在啮齿动物和灵长类动物中所描述的那样。在第二个区域，更靠近羧基末端，四个目之间的高度保守片段的同源性超过90%。后一个片段之一富含半胱氨酸，类似于核酸结合蛋白的推定金属结合结构域，包括TFIIIA和逆转录病毒的金属结合结构域。
