Fourcade-Peronnet F, d'Auriol L, Becker J, Galibert F, Best-Belpomme M
UA CNRS 1135, Université P. et, Paris, France.
Nucleic Acids Res. 1988 Jul 11;16(13):6113-25. doi: 10.1093/nar/16.13.6113.
We have determined the nucleotide sequence of the Drosophila retrotransposon 1731. 1731 is 4648 bp long and is flanked by 336 bp terminal repeats (LTRs) previously described as being reminiscent of provirus LTRs. The 1731 genome consists of two long open reading frames (ORFs 1 and 2) which slightly overlap each other. The ORF 1 and 2 present similarities with retroviral gag and pol genes respectively as shown by computer analysis. The pol gene exhibits several enzymatic activities in the following order: protease, endonuclease and reverse transcriptase. It is possible that 1731 also encompasses a ribonuclease H activity located between the endonuclease and reverse transcriptase domains. Moreover, comparison of the 1731 pol gene with the pol region of copia shows similarities extending over the protease, endonuclease and reverse transcriptase domains. We show that codon usage in the two retrotransposons is different. Finally, no ORF able to encode an env gene is detected in 1731.
我们已经确定了果蝇反转录转座子1731的核苷酸序列。1731长4648 bp，两侧是336 bp的末端重复序列（LTRs），之前描述其让人联想到前病毒LTRs。1731基因组由两个彼此略有重叠的长开放阅读框（ORF 1和ORF 2）组成。计算机分析显示，ORF 1和ORF 2分别与逆转录病毒的gag和pol基因具有相似性。pol基因按以下顺序表现出几种酶活性：蛋白酶、核酸内切酶和逆转录酶。1731可能还包含一种位于核酸内切酶和逆转录酶结构域之间的核糖核酸酶H活性。此外，1731的pol基因与copia的pol区域比较显示，相似性延伸至蛋白酶、核酸内切酶和逆转录酶结构域。我们发现这两个反转录转座子的密码子使用情况不同。最后，在1731中未检测到能够编码env基因的ORF。
