Full length L1 retroposons contain tRNA-like sequences near the 5' termini--hypothesis on the replication mechanism of retroposons.
Retrotransposons replicate via a complex mechanism which depends on, among other things, the presence of long terminal repeats (LTRs) and a tRNA binding site just 3' of the 5' LTR. The LINES 1 (L1) family of sequences, which similar to retrotransposons in many other properties, represents a new class of retroposon which does not possess LTRs. However, we show here that the repetitive 5' motif associated with murine L1 elements contains a tRNA-like sequence in a location analogous to the position of the retro-transposon tRNA binding site. Although the repetition of such a 5' motif has only been found associated with murine L1 elements, we have found an analogous tRNA-like sequence near the 5' ends of the L1 elements from each of the other analyzed species for which the L1 family has been characterized, that is rat (L1Rr), human (L1Hs), drosophila (I element) and trypanosome (INGI). The conservation of this tRNA-like sequence near the 5' terminus of L1 elements from such diverse species suggests that it plays a functional role in the life of the L1 class of retroposon.
Bertling
W M
WM
Max-Planck-Society, University of Erlangen, West Germany.
D000818:Animals; D001483:Base Sequence; D004261:DNA Replication; D004251:DNA Transposable Elements; D051379:Mice / Q000235:genetics*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012343:RNA, Transfer / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D012093:Replicon; D012190:Retroviridae / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
D004251:DNA Transposable Elements; D012343:RNA, Transfer