title: Mutations at position 184 of human immunodeficiency virus type-1 reverse transcriptase affect virus titer and viral DNA synthesis.
abstract: Methionine at position 184 of human immunodeficiency virus type-1 (HIV-1) reverse transcriptase (RT) was changed to valine, isoleucine, threonine, or alanine in an HIV-1-based vector. The vectors were analyzed for replication capacity and for resistance to the nucleoside analog 2',3'-dideoxy-3'thiacytidine (3TC) using a single-cycle assay. Viruses containing the valine or isoleucine mutations were highly resistant to 3TC and replicated almost as well as the wild-type virus. The virus containing the threonine mutation was resistant to 3TC, but replicated about 30% as well as the wild-type. The alanine mutation conferred partial resistance to 3TC, but replicated poorly. The amounts of viral DNA synthesized decreased in 3TC-treated cells when the cells were infected with wild-type virus and the M184A mutant. The effect of these mutations on the generation of the ends of the linear viral DNA was determined using the sequence of the 2-LTR circle junctions. The M184T mutation increased the proportion of 2-LTR circle junctions containing a tRNA insertion, suggesting that the mutation affected the RNase H activity of RT.
authors.affiliation: Basic Research Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, MD 21702-1201, USA.
authors.forename: John G
authors.initials: JG
authors.lastname: Julias
authors.forename: Paul L
authors.initials: PL
authors.lastname: Boyer
authors.forename: Mary Jane
authors.initials: MJ
authors.lastname: McWilliams
authors.forename: W Gregory
authors.initials: WG
authors.lastname: Alvord
authors.forename: Stephen H
authors.initials: SH
authors.lastname: Hughes
mesh_terms: D001665:Binding Sites; D004279:DNA, Viral / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D024882:Drug Resistance, Viral; D054303:HIV Reverse Transcriptase / Q000737:chemistry / Q000235:genetics*; D015497:HIV-1 / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D019259:Lamivudine / Q000494:pharmacology; D008715:Methionine / Q000737:chemistry; D017354:Point Mutation; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology; D016914:Ribonuclease H / Q000378:metabolism; D020079:Terminal Repeat Sequences; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine; D008715:Methionine; D054303:HIV Reverse Transcriptase; D016914:Ribonuclease H