Immunological Relationship of DNA Polymerase from Human Acute Leukaemia Cells and Primate and Mouse Leukaemia Virus Reverse Transcriptase

Nature ◽  
1973 ◽  
Vol 244 (5413) ◽  
pp. 206-209 ◽  
Author(s):  
GEORGE J. TODARO ◽  
ROBERT C. GALLO
Keyword(s):  
Reverse Transcriptase ◽  
Dna Polymerase ◽  
Acute Leukaemia ◽  
Leukaemia Virus ◽  
Immunological Relationship ◽  
Mouse Leukaemia ◽  
Relationship Of

scholarly journals Sulphydryl groups in the template-primer-binding domain of murine leukaemia virus reverse transcriptase. Identification and functional analysis of cysteine-90

1993 ◽  
Vol 296 (3) ◽  
pp. 577-583 ◽  
Author(s):  
S Basu ◽  
A Basu ◽  
M J Modak
Keyword(s):  
Reverse Transcriptase ◽  
Dna Polymerase ◽  
Structural Integrity ◽  
Peptide Mapping ◽  
Site Directed Mutagenesis ◽  
Heat Inactivation ◽  
Composition Analysis ◽  
Kinetic Measurements ◽  
Leukaemia Virus ◽  
Murine Leukaemia Virus

Treatment of murine leukaemia virus reverse transcriptase with benzophenone 4-maleimide inactivates DNA polymerase activity, but has no effect on the RNAase H function. Kinetic measurements indicated that benzophenone 4-maleimide is a competitive inhibitor with respect to template-primer binding, but is non-competitive with respect to dNTP binding. Enzyme modified with benzophenone 4-maleimide cannot bind template-primer or primer alone, as judged by u.v.-mediated cross-linking of radiolabelled substrates. Of the eight cysteine residues in murine leukaemia virus reverse transcriptase, only two were modified by benzophenone 4-maleimide, which were identified as Cys-90 and Cys-310 by comparative tryptic-peptide mapping and amino acid composition analysis. Inclusion of template-primer or primer alone in the modification mixture protected only Cys-90 from modification by benzophenone 4-maleimide. To investigate the role of Cys-90 in detail, we converted it to alanine by site-directed mutagenesis. The mutant enzyme, however, exhibited no loss either of DNA polymerase or of RNAase H activity. These results indicate that Cys-90 is located in a domain of murine leukaemia virus reverse transcriptase that binds template-primer, but may not have a direct role in the enzymic function of the enzyme. Ala-90 mutant murine leukaemia virus reverse transcriptase is at least 10-fold more susceptible to heat inactivation than is the wild-type enzyme, which suggests that Cys-90 in murine leukaemia virus reverse transcriptase may play a role in maintaining structural integrity.

scholarly journals Purification, biochemical characterization and serological analysis of cellular deoxyribonucleic acid polymerases and a reverse transcriptase from spleen of a patient with myelofibrotic syndrome

1977 ◽  
Vol 167 (3) ◽  
pp. 513-524 ◽  
Author(s):  
P Chandra ◽  
L K Steel
Keyword(s):  
Reverse Transcriptase ◽  
Dna Polymerase ◽  
Dna Polymerase Beta ◽  
Human Spleen ◽  
Leukaemia Virus ◽  
Polymerase Gamma ◽  
Dna Polymerase Alpha ◽  
Polymerase Beta ◽  
Dna Polymerase Gamma ◽  
Cellular Dna

The present study describes the separation and purification of a reverse transcriptase and cellular DNA polymerases from the human spleen of a patient with myelofibrotic syndrome. The specific requirements with respect to bivalent cations and template-primers for DNA polymerase-alpha, DNA polymerase-beta and DNA polymerase-gamma, as well as for the reverse transcriptase, are reported. Sedimentation-velocity measurements of the purified enzymes gave values of 150000, 40000, 100000 and 70000 daltons for DNA polymerase-alpha DNA polymerase-beta, DNA polymerase-gamma and the reverse transcriptase respectively. Serological studies have shown that the reverse transcriptase from human spleen is not antigenically related to cellular DNA polymerase-alpha, -beta or -gamma, but is antigenically related to reverse transcriptase from simian sarcoma virus and gibbon-ape leukaemia virus.

scholarly journals Inhibition of murine leukaemia virus reverse transcriptase by 2-halogenated polyadenylic acids

1982 ◽  
Vol 203 (3) ◽  
pp. 755-760 ◽  
Author(s):  
T Fukui ◽  
E De Clercq
Keyword(s):  
Reverse Transcriptase ◽  
Dna Polymerase ◽  
Reverse Transcriptase Activity ◽  
Leukaemia Virus ◽  
Transcriptase Activity ◽  
Murine Leukaemia Virus ◽  
Polyadenylic Acid ◽  
Moloney Murine Leukaemia Virus

Several new analogues of polyadenylic acid [(A)n], i.e. poly(2-fluoroadenylic acid) [(fl2A)n], poly(2-chloroadenylic acid [(cl2A)n], poly(2-bromoadenylic acid) [(br2A)n] and poly(2-iodoadenylic acid) [(io2A)n] have been synthesized and evaluated for their effects on the RNA-directed DNA polymerase (reverse transcriptase) activity of Moloney murine leukaemia virus. All (A)n analogues were found to be potent inhibitors of reverse transcriptase, the order of (decreasing) potency being (fl2A)n greater than (io2A)n greater than (br2A)n greater than (cl2A)n. For all four (A)n analogues the inhibition of reverse transcriptase was competitive with respect to the template-primer. (A)n . oligo(dT). The K1 values were 0.02 microgram/ml for (fl2A)n, 0.1 microgram/ml for (io2A)n, 0.5 microgram/ml for (br2A)n and 8 microgram/ml for (cl2A)n. With a Ki of 0.02 microgram/ml (approx. 0.04 microM), (fl2A)n can be considered as one of the most, if not the most, potent polynucleotide inhibitor of reverse transcriptase that has been described so far.

Suggestive Evidence for an Oncorna-Virus-Specific DNA Polymerase from C-Type Particles of Bovine Leukosis

1974 ◽  
Vol 29 (1-2) ◽  
pp. 72-75 ◽  
Author(s):  
B. Dietzschold ◽  
O.R. Kaaden ◽  
S. Ueberschaer ◽  
F. Weiland ◽  
O. C. Straub
Keyword(s):  
Dna Polymerase ◽  
Polymerase Activity ◽  
Friend Virus ◽  
Leukaemia Virus ◽  
Virus Particles ◽  
Virus Rna ◽  
Feline Leukaemia Virus ◽  
Bovine Leukosis ◽  
Bovine Lymphocytes ◽  
Viral Preparation

Abstract Typical C-type oncorna virus particles as shown by electron microscopy have been purified from the supernatant of cultured lymphocytes from bovine leukosis. In the purified C-particle fraction a DNA-polymerase activity was detected. Using several synthetic RNA-or DNA-homopolymers and 70S Friend virus RNA the template response of this bovine leukosis cell particle DNA polymerase was compared with those of feline leukaemia virus DNA polymerase and DNA polymerase from normal bovine lymphocytes. The DNA polymerase detected in the viral preparation of bovine leukosis is suggested to be an oncorna-virus-specific enzyme.

Synergistic Inhibition of HIV-1 Reverse Transcriptase DNA Polymerase Activity and Virus Replication in Vitro by Combinations of Carboxanilide Nonnucleoside Compounds

Biochemistry ◽  
1995 ◽  
Vol 34 (32) ◽  
pp. 10106-10112 ◽  
Author(s):  
Ronald S. Fletcher ◽  
Dominique Arion ◽  
Gadi Borkow ◽  
Mark A. Wainberg ◽  
Gary I. Dmitrienko ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
Dna Polymerase ◽  
Virus Replication ◽  
Polymerase Activity ◽  
Synergistic Inhibition ◽  
Hiv 1

scholarly journals A Novel Leu92 Mutant of HIV-1 Reverse Transcriptase with a Selective Deficiency in Strand Transfer Causes a Loss of Viral Replication

2015 ◽  
Vol 89 (16) ◽  
pp. 8119-8129 ◽  
Author(s):  
Eytan Herzig ◽  
Nickolay Voronin ◽  
Nataly Kucherenko ◽  
Amnon Hizi
Keyword(s):  
Life Cycle ◽  
Viral Replication ◽  
Reverse Transcriptase ◽  
Dna Polymerase ◽  
Reverse Transcription ◽  
Polymerase Activity ◽  
Rnase H ◽  
Strand Transfer ◽  
Hiv 1

ABSTRACTThe process of reverse transcription (RTN) in retroviruses is essential to the viral life cycle. This key process is catalyzed exclusively by the viral reverse transcriptase (RT) that copies the viral RNA into DNA by its DNA polymerase activity, while concomitantly removing the original RNA template by its RNase H activity. During RTN, the combination between DNA synthesis and RNA hydrolysis leads to strand transfers (or template switches) that are critical for the completion of RTN. The balance between these RT-driven activities was considered to be the sole reason for strand transfers. Nevertheless, we show here that a specific mutation in HIV-1 RT (L92P) that does not affect the DNA polymerase and RNase H activities abolishes strand transfer. There is also a good correlation between this complete loss of the RT's strand transfer to the loss of the DNA clamp activity of the RT, discovered recently by us. This finding indicates a mechanistic linkage between these two functions and that they are both direct and unique functions of the RT (apart from DNA synthesis and RNA degradation). Furthermore, when the RT's L92P mutant was introduced into an infectious HIV-1 clone, it lost viral replication, due to inefficient intracellular strand transfers during RTN, thus supporting thein vitrodata. As far as we know, this is the first report on RT mutants that specifically and directly impair RT-associated strand transfers. Therefore, targeting residue Leu92 may be helpful in selectively blocking this RT activity and consequently HIV-1 infectivity and pathogenesis.IMPORTANCEReverse transcription in retroviruses is essential for the viral life cycle. This multistep process is catalyzed by viral reverse transcriptase, which copies the viral RNA into DNA by its DNA polymerase activity (while concomitantly removing the RNA template by its RNase H activity). The combination and balance between synthesis and hydrolysis lead to strand transfers that are critical for reverse transcription completion. We show here for the first time that a single mutation in HIV-1 reverse transcriptase (L92P) selectively abolishes strand transfers without affecting the enzyme's DNA polymerase and RNase H functions. When this mutation was introduced into an infectious HIV-1 clone, viral replication was lost due to an impaired intracellular strand transfer, thus supporting thein vitrodata. Therefore, finding novel drugs that target HIV-1 reverse transcriptase Leu92 may be beneficial for developing new potent and selective inhibitors of retroviral reverse transcription that will obstruct HIV-1 infectivity.

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