Kulpa Deanna A, Moran John V
Department of Human Genetics 1241 E. Catherine St., University of Michigan Medical School, Ann Arbor, Michigan 48109-0618, USA.
Nat Struct Mol Biol. 2006 Jul;13(7):655-60. doi: 10.1038/nsmb1107. Epub 2006 Jun 18.
LINE-1 retrotransposons (L1s) constitute approximately 17% of human DNA, and their activity continues to affect genome evolution. Retrotransposition-competent human L1s encode two proteins required for their mobility (ORF1p and ORF2p); however, biochemical activities associated with ORF2p have been difficult to detect in cells. Here, we show for the first time the colocalization of L1 RNA, ORF1p and ORF2p to a putative ribonucleoprotein retrotransposition intermediate. We further demonstrate that ORF2p preferentially uses its encoding RNA as a template for reverse transcription. Thus, our data provide the first biochemical evidence supporting the cis-preferential action of the L1 reverse transcriptase.
LINE-1反转录转座子（L1s）约占人类DNA的17%，其活性持续影响基因组进化。具有反转录转座能力的人类L1s编码两种其移动所需的蛋白质（ORF1p和ORF2p）；然而，与ORF2p相关的生化活性在细胞中一直难以检测到。在此，我们首次展示了L1 RNA、ORF1p和ORF2p共定位于一种假定的核糖核蛋白反转录转座中间体。我们进一步证明，ORF2p优先将其编码RNA用作逆转录模板。因此，我们的数据提供了首个支持L1逆转录酶顺式优先作用的生化证据。
