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M3i
Modèles Insectes d’Immunité Innée
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2003
Wilhelm F X, Wilhelm M, Gabriel A
Extension and cleavage of the polypurine tract plus-strand primer by Ty1 reverse transcriptase Article de journal
Dans: J Biol Chem, vol. 278, no. 48, p. 47678-47684, 2003, ISBN: 14500728, (0021-9258 Journal Article).
Résumé | Liens | BibTeX | Étiquettes: Base Sequence DNA/chemistry DNA Primers DNA Replication Models, Calf Thymus/chemistry Support, Genetic, Genetic Molecular Sequence Data Purines/*chemistry RNA/chemistry RNA, Messenger/metabolism RNA, Non-U.S. Gov't Support, P.H.S. Templates, U.S. Gov't, Unité ARN, Viral RNA-Directed DNA Polymerase/*chemistry Recombinant Proteins/chemistry Retroelements/*genetics Ribonuclease H
@article{,
title = {Extension and cleavage of the polypurine tract plus-strand primer by Ty1 reverse transcriptase},
author = {F X Wilhelm and M Wilhelm and A Gabriel},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=14500728},
isbn = {14500728},
year = {2003},
date = {2003-01-01},
journal = {J Biol Chem},
volume = {278},
number = {48},
pages = {47678-47684},
abstract = {Using hybrid RNA/DNA substrates containing the polypurine tract (PPT) plus-strand primer, we have examined the interaction between the Ty1 reverse transcriptase (RT) and the plus-strand initiation complex. We show here that, although the PPT sequence is relatively resistant to RNase H cleavage, it can be cleaved internally by the polymerase-independent RNase H activity of Ty1 RT. Alternatively, this PPT can be used to initiate plus-strand DNA synthesis. We demonstrate that cleavage at the PPT/DNA junction occurs only after at least 9 nucleotides are extended. Cleavage leaves a nick between the RNA primer and the nascent plus-strand DNA. We show that Ty1 RT has a strand displacement activity beyond a gap but that the PPT is not efficiently re-utilized in vitro for another round of DNA synthesis after a first plus-strand DNA has been synthesized and cleaved at the PPT/U3 junction.},
note = {0021-9258
Journal Article},
keywords = {Base Sequence DNA/chemistry DNA Primers DNA Replication Models, Calf Thymus/chemistry Support, Genetic, Genetic Molecular Sequence Data Purines/*chemistry RNA/chemistry RNA, Messenger/metabolism RNA, Non-U.S. Gov't Support, P.H.S. Templates, U.S. Gov't, Unité ARN, Viral RNA-Directed DNA Polymerase/*chemistry Recombinant Proteins/chemistry Retroelements/*genetics Ribonuclease H},
pubstate = {published},
tppubtype = {article}
}
Using hybrid RNA/DNA substrates containing the polypurine tract (PPT) plus-strand primer, we have examined the interaction between the Ty1 reverse transcriptase (RT) and the plus-strand initiation complex. We show here that, although the PPT sequence is relatively resistant to RNase H cleavage, it can be cleaved internally by the polymerase-independent RNase H activity of Ty1 RT. Alternatively, this PPT can be used to initiate plus-strand DNA synthesis. We demonstrate that cleavage at the PPT/DNA junction occurs only after at least 9 nucleotides are extended. Cleavage leaves a nick between the RNA primer and the nascent plus-strand DNA. We show that Ty1 RT has a strand displacement activity beyond a gap but that the PPT is not efficiently re-utilized in vitro for another round of DNA synthesis after a first plus-strand DNA has been synthesized and cleaved at the PPT/U3 junction.
1996
Lanchy J M, Ehresmann C, Grice S F Le, Ehresmann B, Marquet R
Binding and kinetic properties of HIV-1 reverse transcriptase markedly differ during initiation and elongation of reverse transcription Article de journal
Dans: EMBO J, vol. 15, no. 24, p. 7178-7187, 1996, ISBN: 9003793, (0261-4189 Journal Article).
Résumé | Liens | BibTeX | Étiquettes: DNA Primers HIV-1/*enzymology HIV-1 Reverse Transcriptase/*metabolism Kinetics Protein Binding Support, Genetic, Genetic *Transcription, MARQUET, Non-U.S. Gov't Support, P.H.S. Templates, U.S. Gov't, Unité ARN
@article{,
title = {Binding and kinetic properties of HIV-1 reverse transcriptase markedly differ during initiation and elongation of reverse transcription},
author = {J M Lanchy and C Ehresmann and S F Le Grice and B Ehresmann and R Marquet},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=9003793},
isbn = {9003793},
year = {1996},
date = {1996-01-01},
journal = {EMBO J},
volume = {15},
number = {24},
pages = {7178-7187},
abstract = {We recently showed that primer tRNA3Lys, human immunodeficiency virus type 1 (HIV-1) RNA and HIV-1 reverse transcriptase (RT) form a specific complex of initiation of reverse transcription that can be functionally distinguished from the elongation complex, which can be obtained by substituting an 18mer oligodeoxyribonucleotide (ODN) for the natural primer (Isel et al., 1996). Here, we compared the binding properties and the single and multiple turnover kinetics of HIV-1 RT in the initiation and elongation complexes. Even though the equilibrium dissociation constants of HIV-1 RT are not very different for the two complexes, RT dissociates approximately 200-fold faster from the initiation complex. Furthermore, nucleotide incorporation by the pre-formed primer-template-RT complexes is reduced by a approximately 50-fold factor during initiation of reverse transcription, compared with elongation. As a consequence, processivity of HIV-1 RT in the initiation complex is close to unity, while it increases by four orders of magnitude during elongation, as expected for a replication enzyme. This processivity change is reminiscent of the transition from initiation to elongation of transcription. Furthermore, our results indicate that the post-transcriptional modifications of tRNA3Lys play a role similar to that of the sigma factor in transcription by the Escherichia coli RNA polymerase: they favour the formation of the specific initiation complex but do not affect the polymerization rate of the bound enzyme.},
note = {0261-4189
Journal Article},
keywords = {DNA Primers HIV-1/*enzymology HIV-1 Reverse Transcriptase/*metabolism Kinetics Protein Binding Support, Genetic, Genetic *Transcription, MARQUET, Non-U.S. Gov't Support, P.H.S. Templates, U.S. Gov't, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
We recently showed that primer tRNA3Lys, human immunodeficiency virus type 1 (HIV-1) RNA and HIV-1 reverse transcriptase (RT) form a specific complex of initiation of reverse transcription that can be functionally distinguished from the elongation complex, which can be obtained by substituting an 18mer oligodeoxyribonucleotide (ODN) for the natural primer (Isel et al., 1996). Here, we compared the binding properties and the single and multiple turnover kinetics of HIV-1 RT in the initiation and elongation complexes. Even though the equilibrium dissociation constants of HIV-1 RT are not very different for the two complexes, RT dissociates approximately 200-fold faster from the initiation complex. Furthermore, nucleotide incorporation by the pre-formed primer-template-RT complexes is reduced by a approximately 50-fold factor during initiation of reverse transcription, compared with elongation. As a consequence, processivity of HIV-1 RT in the initiation complex is close to unity, while it increases by four orders of magnitude during elongation, as expected for a replication enzyme. This processivity change is reminiscent of the transition from initiation to elongation of transcription. Furthermore, our results indicate that the post-transcriptional modifications of tRNA3Lys play a role similar to that of the sigma factor in transcription by the Escherichia coli RNA polymerase: they favour the formation of the specific initiation complex but do not affect the polymerization rate of the bound enzyme.
Arts E J, Stetor S R, Li X, Rausch J W, Howard K J, Ehresmann B, North T W, Wohrl B M, Goody R S, Wainberg M A, Grice S F
Dans: Proc Natl Acad Sci U S A, vol. 93, no. 19, p. 10063-10068, 1996, ISBN: 8816751, (0027-8424 Journal Article).
Résumé | Liens | BibTeX | Étiquettes: Amino Acyl/chemistry/*metabolism RNA, Animals Base Sequence Cats DNA, Equine/genetics/*metabolism Kinetics Molecular Sequence Data Nucleic Acid Conformation RNA, Genetic, Non-U.S. Gov't Support, P.H.S. Templates, Transfer, U.S. Gov't, Unité ARN, Viral HIV-1/genetics/*metabolism Horses Human Infectious Anemia Virus, Viral/*biosynthesis Genome, Viral/chemistry/*metabolism RNA-Directed DNA Polymerase/*metabolism SIV/genetics/*metabolism Support
@article{,
title = {Initiation of (-) strand DNA synthesis from tRNA(3Lys) on lentiviral RNAs: implications of specific HIV-1 RNA-tRNA(3Lys) interactions inhibiting primer utilization by retroviral reverse transcriptases},
author = {E J Arts and S R Stetor and X Li and J W Rausch and K J Howard and B Ehresmann and T W North and B M Wohrl and R S Goody and M A Wainberg and S F Grice},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=8816751},
isbn = {8816751},
year = {1996},
date = {1996-01-01},
journal = {Proc Natl Acad Sci U S A},
volume = {93},
number = {19},
pages = {10063-10068},
abstract = {Initiation of minus (-) strand DNA synthesis was examined on templates containing R, U5, and primer-binding site regions of the human immunodeficiency virus type 1 (HIV-1), feline immunodeficiency virus (FIV), and equine infectious anemia virus (EIAV) genomic RNA. DNA synthesis was initiated from (i) an oligoribonucleotide complementary to the primer-binding sites, (ii) synthetic tRNA(3Lys), and (iii) natural tRNA(3Lys), by the reverse transcriptases of HIV-1, FIV, EIAV, simian immunodeficiency virus, HIV type 2 (HIV-2), Moloney murine leukemia virus, and avian myeloblastosis virus. All enzymes used an oligonucleotide on wild-type HIV-1 RNA, whereas only a limited number initiated (-) strand DNA synthesis from either tRNA(3Lys). In contrast, all enzymes supported efficient tRNA(3Lys)-primed (-) strand DNA synthesis on the genomes of FIV and EIAV. This may be in part attributable to the observation that the U5-inverted repeat stem-loop of the EIAV and FIV genomes lacks an A-rich loop shown with HIV-1 to interact with the U-rich tRNA anticodon loop. Deletion of this loop in HIV-1 RNA, or disrupting a critical loop-loop complex by tRNA(3Lys) extended by 9 nt, restored synthesis of HIV-1 (-) strand DNA from primer tRNA(3Lys) by all enzymes. Thus, divergent evolution of lentiviruses may have resulted in different mechanisms to use the same host tRNA for initiation of reverse transcription.},
note = {0027-8424
Journal Article},
keywords = {Amino Acyl/chemistry/*metabolism RNA, Animals Base Sequence Cats DNA, Equine/genetics/*metabolism Kinetics Molecular Sequence Data Nucleic Acid Conformation RNA, Genetic, Non-U.S. Gov't Support, P.H.S. Templates, Transfer, U.S. Gov't, Unité ARN, Viral HIV-1/genetics/*metabolism Horses Human Infectious Anemia Virus, Viral/*biosynthesis Genome, Viral/chemistry/*metabolism RNA-Directed DNA Polymerase/*metabolism SIV/genetics/*metabolism Support},
pubstate = {published},
tppubtype = {article}
}
Initiation of minus (-) strand DNA synthesis was examined on templates containing R, U5, and primer-binding site regions of the human immunodeficiency virus type 1 (HIV-1), feline immunodeficiency virus (FIV), and equine infectious anemia virus (EIAV) genomic RNA. DNA synthesis was initiated from (i) an oligoribonucleotide complementary to the primer-binding sites, (ii) synthetic tRNA(3Lys), and (iii) natural tRNA(3Lys), by the reverse transcriptases of HIV-1, FIV, EIAV, simian immunodeficiency virus, HIV type 2 (HIV-2), Moloney murine leukemia virus, and avian myeloblastosis virus. All enzymes used an oligonucleotide on wild-type HIV-1 RNA, whereas only a limited number initiated (-) strand DNA synthesis from either tRNA(3Lys). In contrast, all enzymes supported efficient tRNA(3Lys)-primed (-) strand DNA synthesis on the genomes of FIV and EIAV. This may be in part attributable to the observation that the U5-inverted repeat stem-loop of the EIAV and FIV genomes lacks an A-rich loop shown with HIV-1 to interact with the U-rich tRNA anticodon loop. Deletion of this loop in HIV-1 RNA, or disrupting a critical loop-loop complex by tRNA(3Lys) extended by 9 nt, restored synthesis of HIV-1 (-) strand DNA from primer tRNA(3Lys) by all enzymes. Thus, divergent evolution of lentiviruses may have resulted in different mechanisms to use the same host tRNA for initiation of reverse transcription.