Extension of mismatched 3' termini of DNA is a major determinant of the infidelity of human immunodeficiency virus type 1 reverse transcriptase

F. W. Perrino, B. D. Preston, L. L. Sandell, L. A. Loeb

Research output: Contribution to journalArticlepeer-review

118 Scopus citations

Abstract

The unusually high error rate of human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT) suggests that polymerization errors by this enzyme contribute to the genetic variability of the AIDS virus. We have analyzed the mechanism for HIV-1 RT infidelity by studying two distinct steps that might lead to base substitution mutations: nucleotide misinsertions and elongation from 3'-terminal DNA mispairs. Our results indicate that the capacity of HIV-1 RT to polymerize nucleotides onto mispaired termini is a major factor in the production of mutations by this enzyme. When a noncomplementary dAMP was inserted opposite a template adenine by HIV-1 RT, the nascent 3'-terminal A·A mispair was readily extended by subsequent incorporation of the next complementary nucleotide. The frequencies of nucleotide addition onto 3'-terminal A·A, A·C, and A·G mispairs were determined by quantitating the amount of extended primers with a gel electrophoresis assay and by measuring mutagenesis after hybridization of mismatched primers opposite an amber mutation in bacteriophage ΦX174 DNA. The mispair extension frequencies are ≃50-fold higher by HIV-1 RT than by the mammalian replicative enzyme DNA polymerase α.

Original languageEnglish (US)
Pages (from-to)8343-8347
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume86
Issue number21
DOIs
StatePublished - 1989
Externally publishedYes

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Extension of mismatched 3' termini of DNA is a major determinant of the infidelity of human immunodeficiency virus type 1 reverse transcriptase'. Together they form a unique fingerprint.

Cite this