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Basic Characteristics of Mutations
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Mutation Site
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N815S |
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Mutation Site Sentence
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To determine the mechanism of action of third-generation methylenecyclopropane nucleoside analogs (MCPNAs), DNA sequencing of herpes simplex virus 1 (HSV-1) isolates resistant to third-generation MCPNAs resulted in the discovery of G841S and N815S mutations in HSV-1 UL30. |
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Mutation Level
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Amino acid level |
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Mutation Type
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Nonsynonymous substitution |
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Gene/Protein/Region
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UL30 |
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Standardized Encoding Gene
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UL30
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Genotype/Subtype
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- |
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Viral Reference
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-
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Functional Impact and Mechanisms
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Disease
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Cell line
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Immune
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- |
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Target Gene
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-
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Clinical and Epidemiological Correlations
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Clinical Information
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- |
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Treatment
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MCPNA |
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Location
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- |
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Literature Information
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PMID
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31332074
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Title
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Activation of 6-Alkoxy-Substituted Methylenecyclopropane Nucleoside Analogs Requires Enzymatic Modification by Adenosine Deaminase-Like Protein 1
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Author
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Vollmer KJ,Burns AC,Sauer HE,Williams JD,Komazin-Meredith G,Cardinale S,Butler M,Aron Z,Hussein I,Busch MG,Bowlin TL,Gentry BG
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Journal
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Antimicrobial agents and chemotherapy
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Journal Info
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2019 Sep 23;63(10):e01301-19
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Abstract
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To determine the mechanism of action of third-generation methylenecyclopropane nucleoside analogs (MCPNAs), DNA sequencing of herpes simplex virus 1 (HSV-1) isolates resistant to third-generation MCPNAs resulted in the discovery of G841S and N815S mutations in HSV-1 UL30. Purified HSV-1 UL30 or human cytomegalovirus (HCMV) UL54 was then subjected to increasing concentrations of MBX-2168-triphosphate (TP), with results demonstrating a 50% inhibitory concentration (IC(50)) of approximately 200 muM, indicating that MBX-2168-TP does not inhibit the viral DNA polymerase. Further metabolic studies showed the removal of a moiety on the guanine ring of MBX-2168. Therefore, we hypothesized that enzymatic removal of a moiety at the 6-position of the guanine ring of third-generation MCPNAs is an essential step in activation. To test this hypothesis, pentostatin (deoxycoformycin [dCF]), an adenosine deaminase-like protein 1 (ADAL-1) inhibitor, was coincubated with MBX-2168. The results showed that dCF antagonized the effect of MBX-2168, with a >40-fold increase in the 50% effective concentration (EC(50)) at 50 muM dCF (EC(50) of 63.1 +/- 8.7 muM), compared with MBX-2168 alone (EC(50) of 0.2 +/- 0.1 muM). Purified ADAL-1 demonstrated time-dependent removal of the moiety on the guanine ring of MBX-2168-monophosphate (MP), with a K(m) of 17.5 +/- 2.4 muM and a V(max) of 0.12 +/- 0.04 nmol min(-1) Finally, synguanol-TP demonstrated concentration-dependent inhibition of HSV-1 UL30 and HCMV UL54, with IC(50)s of 0.33 +/- 0.16 and 0.38 +/- 0.11 muM, respectively. We conclude that ADAL-1 is the enzyme responsible for removing the moiety from the guanine ring of MBX-2168-MP prior to conversion to a TP, the active compound that inhibits the viral DNA polymerase.
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Sequence Data
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-
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