Functional characteristics of a reverse transcriptase encoded by an endogenous retrovirus from Drosophila melanogaster.
ZAM is an LTR-retrotransposon from Drosophila melanogaster that belongs to the genus errantivirus, viruses similar in structure and replication cycle to vertebrate retroviruses. A key component to its lifecycle is its reverse transcriptase which copies single-stranded genomic RNA into DNA. Here, we provide a detailed characterization of the enzymatic activities of the reverse transcriptase encoded by ZAM. When expressed in vitro, the reverse transcriptase domain associated with the RNase H domain encoded by the ZAM pol gene forms homodimers and displays an efficient RNA-dependent DNA-polymerase activity. It requires either Mg2+ or Mn2+ divalent cations, and works in basic pH, with a peak at around pH9. The so-called [RT-RH] polypeptide displays an optimal activity at 22 degrees C, a property that makes it well-adapted to the temperature of its host. This study contributes to our understanding of the general structures and functions of retroviral reverse transcriptases, a necessary process in the search for novel inhibitors.
Arnaud
F
F
INSERM U384, Faculty de Medecine, 28 Place Henri Dunant, 63000 Clermont-Ferrand, France.
Peyretaillade
E
E
Dastugue
B
B
Vaury
C
C
D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D017931:DNA Primers; D019281:Dimerization; D004331:Drosophila melanogaster / Q000821:virology*; D007700:Kinetics; D012313:RNA / Q000235:genetics; D012194:RNA-Directed DNA Polymerase / Q000235:genetics* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012190:Retroviridae / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D013816:Thermodynamics
D017931:DNA Primers; D011993:Recombinant Fusion Proteins; D012313:RNA; D004247:DNA; D012194:RNA-Directed DNA Polymerase