Mutations in the catalytic core or the C-terminus of murine leukemia virus (MLV) integrase disrupt virion infectivity and exert diverse effects on reverse transcription.
Understanding of the structures and functions of the retroviral integrase (IN), a key enzyme in the viral replication cycle, is essential for developing antiretroviral treatments and facilitating the development of safer gene therapy vehicles. Thus, four MLV IN-mutants were constructed in the context of a retroviral vector system, harbouring either a substitution in the catalytic centre, deletions in the C-terminus, or combinations of both modifications. IN-mutants were tested for their performance in different stages of the viral replication cycle: RNA-packaging; RT-activity; transient and stable infection efficiency; dynamics of reverse transcription and nuclear entry. All mutant vectors packaged viral RNA with wild-type efficiencies and displayed only slight reductions in RT-activity. Deletion of either the IN C-terminus alone, or in addition to part of the catalytic domain exerted contrasting effects on intracellular viral DNA levels, implying that IN influences reverse transcription in more than one direction.
Steinrigl
Adolf
A
Research Institute for Virology and Biomedicine, University of Veterinary Medicine, A-1210 Vienna, Austria.
Nosek
Dagmara
D
Ertl
Reinhard
R
Günzburg
Walter H
WH
Salmons
Brian
B
Klein
Dieter
D
D019943:Amino Acid Substitution; D000818:Animals; D002460:Cell Line; D004279:DNA, Viral / Q000096:biosynthesis; D006801:Humans; D019426:Integrases / Q000235:genetics / Q000502:physiology*; D009052:Leukemia Virus, Murine / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D051379:Mice; D009154:Mutation; D016133:Polymerase Chain Reaction; D017434:Protein Structure, Tertiary / Q000235:genetics; D048348:Reverse Transcription / Q000235:genetics / Q000502:physiology*; D017384:Sequence Deletion; D014764:Viral Proteins / Q000235:genetics / Q000502:physiology*; D019065:Virus Assembly
D004279:DNA, Viral; D014764:Viral Proteins; D019426:Integrases