Primary structure and functional organization of Drosophila 1731 retrotransposon.
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.
Fourcade-Peronnet
F
F
UA CNRS 1135, Université P. et, Paris, France.
d'Auriol
L
L
Becker
J
J
Galibert
F
F
Best-Belpomme
M
M
D000818:Animals; D001483:Base Sequence; D004254:DNA Nucleotidyltransferases / Q000378:metabolism; D004251:DNA Transposable Elements; D004330:Drosophila / Q000235:genetics; D004722:Endoribonucleases / Q000378:metabolism; D019426:Integrases; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000378:metabolism; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D016914:Ribonuclease H
D004251:DNA Transposable Elements; D004254:DNA Nucleotidyltransferases; D019426:Integrases; D012194:RNA-Directed DNA Polymerase; D004722:Endoribonucleases; D016914:Ribonuclease H; D010447:Peptide Hydrolases