Open AccessSchizosaccharomyces pombe Retrotransposon Tf2 Mobilizes Primarily through Homologous cDNA Recombination
Author(s) -
Eleanor F. Hoff,
Henry L. Levin,
Jef D. Boeke
Publication year - 1998
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.18.11.6839
Subject(s) - retrotransposon , biology , homologous recombination , genetics , schizosaccharomyces pombe , reverse transcriptase , long terminal repeat , schizosaccharomyces , complementary dna , rnase h , virology , genome , transposable element , gene , rna , saccharomyces cerevisiae
The Tf2 retrotransposon, found in the fission yeastSchizosaccharomyces pombe , is nearly identical to its sister element, Tf1, in its reverse transcriptase-RNase H and integrase domains but is very divergent in thegag domain, the protease, the 5′ untranslated region, and the U3 domain of the long terminal repeats. It has now been demonstrated that aneo -marked copy of Tf2 overexpressed from a heterologous promoter can mobilize into theS. pombe genome and produce true transposition events. However, the Tf2-neo mobilization frequency is 10- to 20-fold lower than that of Tf1-neo , and 70% of the Tf2-neo events are homologous recombination events generated independently of a functional Tf2 integrase. Thus, the Tf2 element is primarily dependent on homologous recombination with preexisting copies of Tf2 for its propagation. Finally, production of Tf2-neo proteins and cDNA was also analyzed; surprisingly, Tf2 was found to produce its reverse transcriptase as a single species in which it is fused to protease, unlike all other retroviruses and retrotransposons.