A mutation at one end of Moloney murine leukemia virus DNA blocks cleavage of both ends by the viral integrase in vivo.
The integration of retroviral DNA proceeds through two steps: trimming of the termini to expose new 3' OH ends, and the transfer of those ends to the phosphates of target DNA. We have examined the ability of the Moloney murine leukemia virus integrase protein (IN) to trim the termini of the preintegrative DNA of mutant viruses with alterations in the U3 inverted repeat. The mutant terminus of one replication-defective viral DNA, containing a 7-bp deletion in the U3 inverted repeat, was not trimmed to produce the normal recessed end. Remarkably, the other terminus of this mutant DNA was also not trimmed, even though its sequence is wild type. This finding suggests that the IN protein requires the presence of two good ends before becoming properly activated to trim either one.
Murphy
J E
JE
Department of Biochemistry and Molecular Biophysics, Columbia University College of Physicians and Surgeons, New York, New York 10032.
Goff
S P
SP
D001483:Base Sequence; D002872:Chromosome Deletion; D004254:DNA Nucleotidyltransferases / Q000378:metabolism*; D004279:DNA, Viral / Q000235:genetics* / Q000378:metabolism*; D016679:Genome, Viral; D019426:Integrases; D008969:Molecular Sequence Data; D008979:Moloney murine leukemia virus / Q000201:enzymology / Q000235:genetics*; D016297:Mutagenesis, Site-Directed; D015345:Oligonucleotide Probes; D012091:Repetitive Sequences, Nucleic Acid; D016662:Virus Integration
D004279:DNA, Viral; D015345:Oligonucleotide Probes; D004254:DNA Nucleotidyltransferases; D019426:Integrases