Interaction of 5-Methoxymethyl-2′-Deoxyuridine Triphosphate with DNA Polymerases: Effects of the 5-Substituent and Comparison with the Deoxycytidine Derivative

1992 ◽  
Vol 3 (4) ◽  
pp. 243-247 ◽  
Author(s):  
P. J. Aduma ◽  
S. V. Gupta ◽  
A. L. Stuart
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Dna Polymerase ◽  
Dna Polymerases ◽  
Competitive Inhibitor ◽  
E Coli ◽  
The Difference ◽  
Simplex Virus ◽  
Selective Activity ◽  
Hsv 1

5-Methoxymethyl-2′-deoxyuridine (MMdUrd) is a selective anti-herpes agent that is dependent upon initial phosphorylation by Herpes simplex virus-induced deoxythymidine kinase. In order to determine its mechanism of action, MMdUrd was converted to the 5′-triphosphate (MMdUTP) and the nature of interaction of MMdUTP and dTTP with DNA polymerase of E. coli, HSV-1, and human α was investigated. The order of utilization of deoxyuridine analogues by bacterial and HSV-1 DNA polymerases for DNA synthesis was: dTTP > MMdUTP. In contrast, 5-methoxymethyl-2′-deoxycytidine-5′-triphosphate (MMdCTP) was a better substrate for HSV DNA polymerase compared to dCTP. MMdUTP is a competitive inhibitor of HSV-1 DNA polymerase with respect to dTTP incorporation (Ki = 2.9 × 10−6M). The IC50 values of MMdUTP for both HSV and human αDNA polymerases were 4.5 × 10 −6M. These data suggest that the selective activity of MMdUrd is due to its preferential phosphorylation by viral thymidine kinase and not at the DNA polymerase level. These results may also account for the difference in anti-HSV activity between MMdUrd and its deoxycytidine analogue.

scholarly journals Contrasting Effects of W781V and W780V Mutations in Helix N of Herpes Simplex Virus 1 and Human Cytomegalovirus DNA Polymerases on Antiviral Drug Susceptibility

2015 ◽  
Vol 89 (8) ◽  
pp. 4636-4644 ◽  
Author(s):  
Jocelyne Piret ◽  
Nathalie Goyette ◽  
Brian E. Eckenroth ◽  
Emilien Drouot ◽  
Matthias Götte ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Dna Polymerase ◽  
Dna Polymerases ◽  
Antiviral Drug ◽  
Drug Susceptibility ◽  
Herpes Simplex Virus 1 ◽  
Simplex Virus ◽  
Antiviral Drug Susceptibility ◽  
Hsv 1

ABSTRACTDNA polymerases of theHerpesviridaeand bacteriophage RB69 belong to the α-like DNA polymerase family. In spite of similarities in structure and function, the RB69 enzyme is relatively resistant to foscarnet, requiring the mutation V478W in helix N to promote the closed conformation of the enzyme to make it susceptible to the antiviral. Here, we generated recombinant herpes simplex virus 1 (HSV-1) and human cytomegalovirus (HCMV) mutants harboring the revertant in UL30 (W781V) and UL54 (W780V) DNA polymerases, respectively, to further investigate the impact of this tryptophan on antiviral drug susceptibility and viral replicative capacity. The mutation W781V in HSV-1 induced resistance to foscarnet, acyclovir, and ganciclovir (3-, 14-, and 3-fold increases in the 50% effective concentrations [EC50s], respectively). The recombinant HCMV mutant harboring the W780V mutation was slightly resistant to foscarnet (a 1.9-fold increase in the EC50) and susceptible to ganciclovir. Recombinant HSV-1 and HCMV mutants had altered viral replication kinetics. The apparent inhibition constant values of foscarnet against mutant UL30 and UL54 DNA polymerases were 45- and 4.9-fold higher, respectively, than those against their wild-type counterparts. Structural evaluation of the tryptophan position in the UL54 DNA polymerase suggests that the bulkier phenylalanine (fingers domain) and isoleucine (N-terminal domain) could induce a tendency toward the closed conformation greater than that for UL30 and explains the modest effect of the W780V mutation on foscarnet susceptibility. Our results further suggest a role of the tryptophan in helix N in conferring HCMV and especially HSV-1 susceptibility to foscarnet and the possible contribution of other residues localized at the interface between the fingers and N-terminal domains.IMPORTANCEDNA polymerases of theHerpesviridaeand bacteriophage RB69 belong to the α-like DNA polymerase family. However, the RB69 DNA polymerase is relatively resistant to the broad-spectrum antiviral agent foscarnet. The mutation V478W in helix N of the fingers domain caused the enzyme to adopt a closed conformation and to become susceptible to the antiviral. We generated recombinant herpes simplex virus 1 (HSV-1) and human cytomegalovirus (HCMV) mutants harboring the revertant in UL30 (W781V) and UL54 (W780V) DNA polymerases, respectively, to further investigate the impact of this tryptophan on antiviral drug susceptibility. The W781V mutation in HSV-1 induced resistance to foscarnet, whereas the W780V mutation in HCMV slightly decreased drug susceptibility. This study suggests that the different profiles of susceptibility to foscarnet of the HSV-1 and HCMV mutants could be related to subtle conformational changes resulting from the interaction between residues specific to each enzyme that are located at the interface between the fingers and the N-terminal domains.

scholarly journals Antiviral activity of the 3′;-amino derivative of (E)-5-(2-bromovinyl)-2′;-deoxyuridine

1983 ◽  
Vol 211 (2) ◽  
pp. 439-445 ◽  
Author(s):  
E De Clercq ◽  
J Descamps ◽  
J Balzarini ◽  
T Fukui ◽  
H S Allaudeen
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Thymidine Kinase ◽  
Dna Polymerase ◽  
Dna Polymerases ◽  
Amino Derivative ◽  
Dna Polymerase Alpha ◽  
Simplex Virus ◽  
Hsv 1

3′-NH2-BV-dUrd, the 3′-amino derivative of (E)-5-(2-bromovinyl)-2′-deoxyuridine, was found to be a potent and selective inhibitor of herpes simplex virus type 1 (HSV-1) and varicella-zoster virus (VZV) replication. 3′-NH2-BV-dUrd was about 4-12 times less potent but equally selective in its anti-herpes activity as BV-dUrd. Akin to BV-dUrd, 3′-NH2-BV-dUrd was much less inhibitory to herpes simplex virus type 2 than type 1. It was totally inactive against a thymidine kinase-deficient mutant of HSV-1. The 5′-triphosphate of 3′-NH2-BV-dUrd (3′-NH2-BV-dUTP) was evaluated for its inhibitory effects on purified herpes viral and cellular DNA polymerases. Among the DNA polymerases tested, HSV-1 DNA polymerase and DNA polymerase alpha were the most sensitive to inhibition by 3′-NH2-BV-dUTP (Ki values 0.13 and 0.10 microM, respectively). The Km/Ki ratio for DNA polymerase alpha was 47, as compared with 4.6 for HSV-1 DNA polymerase. Thus, the selectivity of 3′-NH2-BV-dUrd as an anti-herpes agent cannot be ascribed to a discriminative effect of its 5′-triphosphate at the DNA polymerase level. This selectivity most probably resides at the thymidine kinase level. 3′;-NH2-BV-dUrd would be phosphorylated preferentially by the HSV-1-induced thymidine kinase (Ki 1.9 microM, as compared with greater than 200 microM for the cellular thymidine kinase), and this preferential phosphorylation would confine the further action of the compound to the virus-infected cell.

scholarly journals Amino Acid Changes within Conserved Region III of the Herpes Simplex Virus and Human Cytomegalovirus DNA Polymerases Confer Resistance to 4-Oxo-Dihydroquinolines, a Novel Class of Herpesvirus Antiviral Agents

2003 ◽  
Vol 77 (3) ◽  
pp. 1868-1876 ◽  
Author(s):  
Darrell R. Thomsen ◽  
Nancee L. Oien ◽  
Todd A. Hopkins ◽  
Mary L. Knechtel ◽  
Roger J. Brideau ◽  
...  
Keyword(s):  
Amino Acid ◽  
Herpes Simplex ◽  
Dna Polymerase ◽  
Dna Polymerases ◽  
Nucleoside Analogs ◽  
Polymerase Activity ◽  
Conserved Domain ◽  
Domain Iii ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT The 4-oxo-dihydroquinolines (PNU-182171 and PNU-183792) are nonnucleoside inhibitors of herpesvirus polymerases (R. J. Brideau et al., Antiviral Res. 54:19-28, 2002; N. L. Oien et al., Antimicrob. Agents Chemother. 46:724-730, 2002). In cell culture these compounds inhibit herpes simplex virus type 1 (HSV-1), HSV-2, human cytomegalovirus (HCMV), varicella-zoster virus (VZV), and human herpesvirus 8 (HHV-8) replication. HSV-1 and HSV-2 mutants resistant to these drugs were isolated and the resistance mutation was mapped to the DNA polymerase gene. Drug resistance correlated with a point mutation in conserved domain III that resulted in a V823A change in the HSV-1 or the equivalent amino acid in the HSV-2 DNA polymerase. Resistance of HCMV was also found to correlate with amino acid changes in conserved domain III (V823A+V824L). V823 is conserved in the DNA polymerases of six (HSV-1, HSV-2, HCMV, VZV, Epstein-Barr virus, and HHV-8) of the eight human herpesviruses; the HHV-6 and HHV-7 polymerases contain an alanine at this amino acid. In vitro polymerase assays demonstrated that HSV-1, HSV-2, HCMV, VZV, and HHV-8 polymerases were inhibited by PNU-183792, whereas the HHV-6 polymerase was not. Changing this amino acid from valine to alanine in the HSV-1, HCMV, and HHV-8 polymerases alters the polymerase activity so that it is less sensitive to drug inhibition. In contrast, changing the equivalent amino acid in the HHV-6 polymerase from alanine to valine alters polymerase activity so that PNU-183792 inhibits this enzyme. The HSV-1, HSV-2, and HCMV drug-resistant mutants were not altered in their susceptibilities to nucleoside analogs; in fact, some of the mutants were hypersensitive to several of the drugs. These results support a mechanism where PNU-183792 inhibits herpesviruses by interacting with a binding determinant on the viral DNA polymerase that is less important for the binding of nucleoside analogs and deoxynucleoside triphosphates.

scholarly journals Herpes Simplex Virus 1 DNA Polymerase RNase H Activity Acts in a 3′-to-5′ Direction and Is Dependent on the 3′-to-5′ Exonuclease Active Site

2017 ◽  
Vol 92 (5) ◽  
Author(s):  
Jessica L. Lawler ◽  
Purba Mukherjee ◽  
Donald M. Coen
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Dna Polymerase ◽  
Polymerase Activity ◽  
Rnase H ◽  
Exonuclease Activity ◽  
Wild Type ◽  
Herpes Simplex Virus 1 ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACTThe catalytic subunit (Pol) of herpes simplex virus 1 (HSV-1) DNA polymerase has been extensively studied both as a model for other family B DNA polymerases and for its differences from these enzymes as an antiviral target. Among the activities of HSV-1 Pol is an intrinsic RNase H activity that cleaves RNA from RNA-DNA hybrids. There has long been a controversy regarding whether this activity is due to the 3′-to-5′ exonuclease of Pol or whether it is a separate activity, possibly acting on 5′ RNA termini. To investigate this issue, we compared wild-type HSV-1 Pol and a 3′-to-5′ exonuclease-deficient mutant, D368A Pol, for DNA polymerase activity, 3′-to-5′ exonuclease activity, and RNase H activityin vitro. Additionally, we assessed the RNase H activity using differentially end-labeled templates with 5′ or 3′ RNA termini. The mutant enzyme was at most modestly impaired for DNA polymerase activity but was drastically impaired for 3′-to-5′ exonuclease activity, with no activity detected even at high enzyme-to-DNA substrate ratios. Importantly, the mutant showed no detectable ability to excise RNA with either a 3′ or 5′ terminus, while the wild-type HSV-1 Pol was able to cleave RNA from the annealed RNA-DNA hairpin template, but only detectably with a 3′ RNA terminus in a 3′-to-5′ direction and at a rate lower than that of the exonuclease activity. These results suggest that HSV-1 Pol does not have an RNase H separable from its 3′-to-5′ exonuclease activity and that this activity prefers DNA degradation over degradation of RNA from RNA-DNA hybrids.IMPORTANCEHerpes simplex virus 1 (HSV-1) is a member of theHerpesviridaefamily of DNA viruses, several of which cause morbidity and mortality in humans. Although the HSV-1 DNA polymerase has been studied for decades and is a crucial target for antivirals against HSV-1 infection, several of its functions remain to be elucidated. A hypothesis suggesting the existence of a 5′-to-3′ RNase H activity intrinsic to this enzyme that could remove RNA primers from Okazaki fragments has been particularly controversial. In this study, we were unable to identify RNase H activity of HSV-1 DNA polymerase on RNA-DNA hybrids with 5′ RNA termini. We detected RNase H activity on hybrids with 3′ termini, but this was due to the 3′-to-5′ exonuclease. Thus, HSV-1 is unlikely to use this method to remove RNA primers during DNA replication but may use pathways similar to those used in eukaryotic Okazaki fragment maturation.

scholarly journals 3′ to 5′ Exonuclease Activity of Herpes Simplex Virus Type 1 DNA Polymerase Modulates Its Strand Displacement Activity

2003 ◽  
Vol 77 (18) ◽  
pp. 10147-10153 ◽  
Author(s):  
Yali Zhu ◽  
Kelly S. Trego ◽  
Liping Song ◽  
Deborah S. Parris
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Dna Polymerase ◽  
Virus Type ◽  
Herpes Simplex Virus Type ◽  
Strand Displacement ◽  
Displacement Activity ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT Using a minicircle DNA primer-template, the wild-type catalytic subunit of herpes simplex virus type 1 (HSV-1) DNA polymerase (pol) was shown to lack significant strand displacement activity with or without its processivity factor, UL42. However, an exonuclease-deficient (exo−) pol (D368A) was capable of slow strand displacement. Although UL42 increased the rate (2/s) and processivity of strand displacement by exo− pol, the rate was slower than that for gap-filling synthesis. High inherent excision rates on matched primer-templates and rapid idling-turnover (successive rounds of excision and polymerization) of exo-proficient polymerases correlated with poor strand displacement activity. The results suggest that the exo activity of HSV-1 pol modulates its ability to engage in strand displacement, a function that may be important to the viability and genome stability of the virus.

scholarly journals Sequence Analysis of Herpes Simplex Virus 1 Thymidine Kinase and DNA Polymerase Genes from over 300 Clinical Isolates from 1973 to 2014 Finds Novel Mutations That May Be Relevant for Development of Antiviral Resistance

2015 ◽  
Vol 59 (8) ◽  
pp. 4938-4945 ◽  
Author(s):  
Susanne Schmidt ◽  
Kathrin Bohn-Wippert ◽  
Peter Schlattmann ◽  
Roland Zell ◽  
Andreas Sauerbrei
Keyword(s):  
Herpes Simplex Virus ◽  
Amino Acid ◽  
Herpes Simplex ◽  
Thymidine Kinase ◽  
Dna Polymerase ◽  
Herpes Simplex Virus 1 ◽  
Immunosuppressed Patients ◽  
Resistant Strains ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACTA total of 302 clinical herpes simplex virus 1 (HSV-1) strains, collected over 4 decades from 1973 to 2014, were characterized retrospectively for drug resistance. All HSV-1 isolates were analyzed genotypically for nonsynonymous mutations in the thymidine kinase (TK) and DNA polymerase (Pol) genes. The resistance phenotype against acyclovir (ACV) and/or foscarnet (FOS) was examined in the case of novel, unclear, or resistance-related mutations. Twenty-six novel natural polymorphisms could be detected in the TK gene and 69 in the DNA Pol gene. Furthermore, three novel resistance-associated mutations (two in the TK gene and one in the DNA Pol gene) were analyzed, and eight known but hitherto unclear amino acid substitutions (two encoded in TK and six in the DNA Pol gene) could be clarified. Between 1973 and 2014, the distribution of amino acid changes related to the natural gene polymorphisms of TK and DNA Pol remained largely stable. Resistance to ACV was confirmed phenotypically for 16 isolates, and resistance to ACV plus FOS was confirmed for 1 isolate. Acyclovir-resistant strains were observed from the year 1995 onwards, predominantly in immunosuppressed patients, especially those with stem cell transplantation, and the number of ACV-resistant strains increased during the last 2 decades. The data confirm the strong genetic variability among HIV-1 isolates, which is more pronounced in the DNA Pol gene than in the TK gene, and will facilitate considerably the rapid genotypic diagnosis of HSV-1 resistance.

scholarly journals Roles of conserved residues within the pre-NH2-terminal domain of herpes simplex virus 1 DNA polymerase in replication and latency in mice

2014 ◽  
Vol 95 (4) ◽  
pp. 940-947 ◽  
Author(s):  
Shariya L. Terrell ◽  
Jean M. Pesola ◽  
Donald M. Coen
Keyword(s):  
Cell Culture ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Dna Synthesis ◽  
Dna Polymerase ◽  
Infectious Virus ◽  
Viral Dna ◽  
Herpes Simplex Virus 1 ◽  
Simplex Virus ◽  
Hsv 1

The catalytic subunit of the herpes simplex virus 1 DNA polymerase (HSV-1 Pol) is essential for viral DNA synthesis and production of infectious virus in cell culture. While mutations that affect 5′–3′ polymerase activity have been evaluated in animal models of HSV-1 infection, mutations that affect other functions of HSV-1 Pol have not. In a previous report, we utilized bacterial artificial chromosome technology to generate defined HSV-1 pol mutants with lesions in the previously uncharacterized pre-NH2-terminal domain. We found that the extreme N-terminal 42 residues (deletion mutant polΔN43) were dispensable for replication in cell culture, while residues 44–49 (alanine-substitution mutant polA6) were required for efficient viral DNA synthesis and production of infectious virus. In this study, we sought to address the importance of these conserved elements in viral replication in a mouse corneal infection model. Mutant virus polΔN43 exhibited no meaningful defect in acute or latent infection despite strong conservation of residues 1–42 with HSV-2 Pol. The polA6 mutation caused a modest defect in replication at the site of inoculation, and was severely impaired for ganglionic replication, even at high inocula that permitted efficient corneal replication. Additionally, the polA6 mutation resulted in reduced latency establishment and subsequent reactivation. Moreover, we found that the polA6 replication defect in cultured cells was exacerbated in resting cells as compared to dividing cells. These results reveal an important role for the conserved motif at residues 44–49 of HSV-1 Pol for ganglionic viral replication.

scholarly journals Evidence of Muller’s ratchet in herpes simplex virus type 1

2013 ◽  
Vol 94 (2) ◽  
pp. 366-375 ◽  
Author(s):  
Nacarí Jaramillo ◽  
Esteban Domingo ◽  
María Carmen Muñoz-Egea ◽  
Enrique Tabarés ◽  
Ignacio Gadea
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Dna Polymerase ◽  
Herpes Simplex Virus Type ◽  
Rna Viruses ◽  
Population Bottlenecks ◽  
Dna Viruses ◽  
Simplex Virus ◽  
Hsv 1

Population bottlenecks can have major effects in the evolution of RNA viruses, but their possible influence in the evolution of DNA viruses is largely unknown. Genetic and biological variation of herpes simplex virus type 1 (HSV-1) has been studied by subjecting 23 biological clones of the virus to 10 plaque-to-plaque transfers. In contrast to large population passages, plaque transfers led to a decrease in replicative capacity of HSV-1. Two out of a total of 23 clones did not survive to the last transfer in 143 TK– cells. DNA from three genomic regions (DNA polymerase, glycoprotein gD and thymidine kinase) from the initial and passaged clones was sequenced. Nucleotide substitutions were detected in the TK and gD genes, but not in the DNA polymerase gene. Assuming a uniform distribution of mutations along the genome, the average rate of fixation of mutations was about five mutations per viral genome and plaque transfer. This value is comparable to the range of values calculated for RNA viruses. Four plaque-transferred populations lost neurovirulence for mice, as compared with the corresponding initial clones. LD50 values obtained with the populations subjected to serial bottlenecks were 4- to 67-fold higher than for their parental clones. These results equate HSV-1 with RNA viruses regarding fitness decrease as a result of plaque–to-plaque transfers, and show that population bottlenecks can modify the pathogenic potential of HSV-1. Implications for the evolution of complex DNA viruses are discussed.

scholarly journals Drug Resistance Patterns of Recombinant Herpes Simplex Virus DNA Polymerase Mutants Generated with a Set of Overlapping Cosmids and Plasmids

2003 ◽  
Vol 77 (14) ◽  
pp. 7820-7829 ◽  
Author(s):  
Julie Bestman-Smith ◽  
Guy Boivin
Keyword(s):  
Drug Resistance ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Dna Polymerase ◽  
Cross Resistance ◽  
Replication Capacity ◽  
Conserved Regions ◽  
Simplex Virus ◽  
New System ◽  
Hsv 1

ABSTRACT Herpes simplex virus (HSV) DNA polymerase (Pol) mutations can confer resistance to all currently available antiherpetic drugs. However, discrimination between mutations responsible for drug resistance and those that are part of viral polymorphism can be difficult with current methodologies. A new system is reported for rapid generation of recombinant HSV type 1 (HSV-1) DNA Pol mutants based on transfection of a set of overlapping viral cosmids and plasmids. With this approach, twenty HSV-1 recombinants with single or dual mutations within the DNA pol gene were successfully generated and subsequently evaluated for their susceptibilities to acyclovir (ACV), foscarnet (FOS), cidofovir (CDV), and adefovir (ADV). Mutations within DNA Pol conserved regions II (A719T and S724N), VI (L778M, D780N, and L782I), and I (F891C) were shown to induce cross-resistance to ACV, FOS, and ADV, with two of these mutations (S724N and L778M) also conferring significant reduction in CDV susceptibility. Mutant F891C was associated with the highest levels of resistance towards ACV and FOS and was strongly impaired in its replication capacity. One mutation (D907V) lying outside of the conserved regions was also associated with this ACV-, FOS-, and ADV-resistant phenotype. Some mutations (K522E and Y577H) within the δ-region C were lethal, whereas others (P561S and V573M) induced no resistance to any of the drugs tested. Recombinants harboring mutations within conserved regions V (N961K) and VII (Y941H) were resistant to ACV but susceptible to FOS. Finally, mutations within conserved region III were associated with various susceptibility profiles. This new system allows a rapid and accurate evaluation of the functional role of various DNA Pol mutations, which should translate into improved management of drug-resistant HSV infections.

scholarly journals Kinetic Approaches to Understanding the Mechanisms of Fidelity of the Herpes Simplex Virus Type 1 DNA Polymerase

2010 ◽  
Vol 2010 ◽  
pp. 1-15 ◽  
Author(s):  
Yali Zhu ◽  
Jason Stroud ◽  
Liping Song ◽  
Deborah S. Parris
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Dna Polymerase ◽  
Virus Type ◽  
Herpes Simplex Virus Type ◽  
Active Sites ◽  
Replicative Polymerases ◽  
Simplex Virus ◽  
Hsv 1

We discuss how the results of presteady-state and steady-state kinetic analysis of the polymerizing and excision activities of herpes simplex virus type 1 (HSV-1) DNA polymerase have led to a better understanding of the mechanisms controlling fidelity of this important model replication polymerase. Despite a poorer misincorporation frequency compared to other replicative polymerases with intrinsic 3′to 5′exonuclease (exo) activity, HSV-1 DNA replication fidelity is enhanced by a high kinetic barrier to extending a primer/template containing a mismatch or abasic lesion and by the dynamic ability of the polymerase to switch the primer terminus between the exo and polymerizing active sites. The HSV-1 polymerase with a catalytically inactivated exo activity possesses reduced rates of primer switching and fails to support productive replication, suggesting a novel means to target polymerase for replication inhibition.

Sign in / Sign up

Export Citation Format

Share Document