Human endogenous retrovirus K10 encodes a functional integrase.
We cloned a human endogenous retrovirus K1O DNA fragment encoding integrase and expressed it as a fusion protein with Escherichia coli maltose-binding protein. Integrase activities were measured in vitro by using a double-stranded oligonucleotide as a substrate mimicking viral long terminal repeats (LTR). The fusion protein was highly active for both terminal cleavage and strand transfer in the presence of Mn2+ on the K1O LTR substrate. It was also active on both Rous sarcoma virus and human immunodeficiency virus type 1 LTR substrates, whereas Rous sarcoma virus and human immunodeficiency virus type 1 integrases were active only on their corresponding LTR substrates. The results strongly suggest that K1O encodes a functional integrase with relaxed substrate specificity.
Kitamura
Y
Y
Division of Molecular Genetics, National Institute of Health, Tokyo, Japan.
Ayukawa
T
T
Ishikawa
T
T
Kanda
T
T
Yoshiike
K
K
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004254:DNA Nucleotidyltransferases / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D017931:DNA Primers; D004926:Escherichia coli; D006801:Humans; D019426:Integrases; D008345:Manganese / Q000494:pharmacology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D012190:Retroviridae / Q000201:enzymology* / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013379:Substrate Specificity
D017931:DNA Primers; D011994:Recombinant Proteins; D008345:Manganese; D004254:DNA Nucleotidyltransferases; D019426:Integrases