The avian retroviral IN protein is both necessary and sufficient for integrative recombination in vitro.
The integration of viral DNA into the host cell chromosome is an essential feature of the retroviral life cycle. The integration reaction requires cis-acting sequences at the ends of linear viral DNA and a trans-acting product of the pol gene, the integration protein (IN). Previously, we demonstrated that avian sarcoma-leukosis virus (ASLV) IN is able to carry out the first step in the integration process in vitro: nicking of the ends of linear viral DNA. In this paper, using two independent assays, we demonstrate that IN, alone, is sufficient to carry out the second step: cleavage and joining to the target DNA. These results demonstrate that the retroviral IN protein is an integrase.
Katz
R A
RA
Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111.
Merkel
G
G
Kulkosky
J
J
Leis
J
J
Skalka
A M
AM
D001355:Alpharetrovirus / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D004254:DNA Nucleotidyltransferases / Q000378:metabolism*; D004279:DNA, Viral / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D019426:Integrases; D008957:Models, Genetic; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D010957:Plasmids; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid
D004279:DNA, Viral; D015345:Oligonucleotide Probes; D004254:DNA Nucleotidyltransferases; D019426:Integrases