scholarly journals Structural determinants of murine leukemia virus reverse transcriptase that are important for template switching, fidelity, and drug resistance

2000 ◽  
Author(s):  
Evguenia S. Svarovskaia
Keyword(s):  
Drug Resistance ◽  
Reverse Transcriptase ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Template Switching ◽  
Structural Determinants ◽  
Murine Leukemia

scholarly journals Structure-Based Moloney Murine Leukemia Virus Reverse Transcriptase Mutants with Altered Intracellular Direct-Repeat Deletion Frequencies

2000 ◽  
Vol 74 (20) ◽  
pp. 9629-9636 ◽  
Author(s):  
Julie K. Pfeiffer ◽  
Millie M. Georgiadis ◽  
Alice Telesnitsky
Keyword(s):  
Reverse Transcriptase ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Direct Repeat ◽  
Moloney Murine Leukemia Virus ◽  
Wild Type Virus ◽  
Template Switching ◽  
Wild Type ◽  
Catalytic Core ◽  
Murine Leukemia

ABSTRACT Template switching rates of Moloney murine leukemia virus reverse transcriptase mutants were tested using a retroviral vector-based direct-repeat deletion assay. The reverse transcriptase mutants contained alterations in residues that modeling of substrates into the catalytic core had suggested might affect interactions with primer and/or template strands. As assessed by the frequency of functionallacZ gene generation from vectors in which lacZwas disrupted by insertion of a sequence duplication, the frequency of template switching varied more than threefold among fully replication-competent mutants. Some mutants displayed deletion rates that were lower and others displayed rates that were higher than that of wild-type virus. Replication for the mutants with the most significant alterations in template switching frequencies was similar to that of the wild type. These data suggest that reverse transcriptase template switching rates can be altered significantly without destroying normal replication functions.

scholarly journals Altering the Intracellular Environment Increases the Frequency of Tandem Repeat Deletion during Moloney Murine Leukemia Virus Reverse Transcription

1999 ◽  
Vol 73 (10) ◽  
pp. 8441-8447 ◽  
Author(s):  
Julie K. Pfeiffer ◽  
Robert S. Topping ◽  
Nam-Hee Shin ◽  
Alice Telesnitsky
Keyword(s):  
Reverse Transcriptase ◽  
Tandem Repeat ◽  
Reverse Transcription ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Moloney Murine Leukemia Virus ◽  
Template Switching ◽  
Intracellular Environment ◽  
Time Required ◽  
Murine Leukemia

ABSTRACT During retroviral DNA synthesis reverse transcriptase frequently performs nonrequired template switches that can lead to genetic rearrangements or recombination. It has been postulated that template switching occurs after pauses in the action of reverse transcriptase. Hence factors which affect pausing, such as polymerization rate, may affect the frequency of template switching. To address the hypothesis that increasing the time required to complete reverse transcription increases the frequency of template switching, we established conditions that lengthened the time required to complete a single round of intracellular Moloney murine leukemia virus reverse transcription approximately threefold. Under these conditions, which resulted from intracellular nucleotide pool imbalances generated with hydroxyurea, we examined template switching frequency using a lacZ-based tandem repeat deletion assay. We observed that the frequency of deletion during reverse transcription in hydroxyurea-treated cells was approximately threefold higher than that in untreated control cells. These findings suggest that rates of retroviral recombination may vary when the intracellular environment is altered.

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