Reverse transcriptase encoded by a human transposable element.
L1 elements are highly repeated mammalian DNA sequences whose structure suggests dispersal by retrotransposition. A consensus L1 element encodes a protein with sequence similarity to known reverse transcriptases. The second open reading frame from the human L1 element L1.2A was expressed as a fusion protein targeted to Ty1 virus-like particles in Saccharomyces cerevisiae and shown to have reverse transcriptase activity. This activity was eliminated by a missense mutation in the highly conserved amino acid motif Y/F-X-D-D. Thus, L1 represents a potential source of the reverse transcriptase activity necessary for dispersion of the many classes of mammalian retroelements.
Mathias
S L
SL
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Scott
A F
AF
Kazazian
H H
HH
Boeke
J D
JD
Gabriel
A
A
D001483:Base Sequence; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D000939:Epitopes / Q000032:analysis; D006801:Humans; D015151:Immunoblotting; D007700:Kinetics; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D016366:Open Reading Frames; D010957:Plasmids; D011131:Polyribonucleotides; D012194:RNA-Directed DNA Polymerase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D013698:Templates, Genetic
D004251:DNA Transposable Elements; D000939:Epitopes; D009838:Oligodeoxyribonucleotides; D011131:Polyribonucleotides; D011993:Recombinant Fusion Proteins; D012194:RNA-Directed DNA Polymerase