Biological evaluation of hepatitis c virus helicase inhibitors

Phoon, Chee Wee; Ng, Poh Yong; Ting, Anthony E.; Yeo, Su Ling; Sim, Melvyn

doi:10.1016/s0960-894x(01)00263-3

Cited by 81 publications

(52 citation statements)

References 5 publications

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“…Screening of chemical libraries has identified limited numbers of weak helicase inhibitors. 212 HCV helicase activity is inhibited in vitro by recombinant antibodies, 213,214 by RNA aptamers 215,216 and by peptides. 217,218 Targeting the nucleotide binding site of HCV-NS3 has proven exceedingly difficult, 219 although nucleotide-mimicking competitive inhibitors have been identified.…”

Section: Rna Helicases As Drug Targetsmentioning

confidence: 99%

RNA helicases in infection and disease

Steimer

Klostermeier

2012

RNA Biology

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Section: Rna Helicases As Drug Targetsmentioning

confidence: 99%

RNA helicases in infection and disease

Steimer

Klostermeier

2012

RNA Biology

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“…Alternatively, equation 2 could be used to yield a value for K D as previously described (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)53):…”

Section: Methodsmentioning

confidence: 99%

“…As a result, helicases are key players in a wide variety of DNA and RNA metabolic processes, such as recombination, chromatin remodeling, and DNA transport (4)(5)(6). Most recently, helicases have emerged as potential therapeutic targets for diseases ranging from cancer to Gram-positive bacterial infections (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). Classified into six superfamilies, superfamily 1 and 2 (SF1 and SF2) helicases are the most similar, sharing up to seven conserved sequence motifs and core RecA-like folds (1)(2)(3).…”

mentioning

confidence: 99%

Unique Helicase Determinants in the Essential Conjugative TraI Factor from Salmonella enterica Serovar Typhimurium Plasmid pCU1

2014

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The widespread development of multidrug-resistant bacteria is a major health emergency. Conjugative DNA plasmids, which harbor a wide range of antibiotic resistance genes, also encode the protein factors necessary to orchestrate the propagation of plasmid DNA between bacterial cells through conjugative transfer. Successful conjugative DNA transfer depends on key catalytic components to nick one strand of the duplex DNA plasmid and separate the DNA strands while cell-to-cell transfer occurs. The TraI protein from the conjugative Salmonella plasmid pCU1 fulfills these key catalytic roles, as it contains both single-stranded DNA-nicking relaxase and ATP-dependent helicase domains within a single, 1,078-residue polypeptide. In this work, we unraveled the helicase determinants of Salmonella pCU1 TraI through DNA binding, ATPase, and DNA strand separation assays. TraI binds DNA substrates with high affinity in a manner influenced by nucleic acid length and the presence of a DNA hairpin structure adjacent to the nick site. TraI selectively hydrolyzes ATP, and mutations in conserved helicase motifs eliminate ATPase activity. Surprisingly, the absence of a relatively short (144-residue) domain at the extreme C terminus of the protein severely diminishes ATP-dependent strand separation. Collectively, these data define the helicase motifs of the conjugative factor TraI from Salmonella pCU1 and reveal a previously uncharacterized C-terminal functional domain that uncouples ATP hydrolysis from strand separation activity.H elicases are molecular motors that drive the separation of duplex nucleic acid strands through the coupling of ATP hydrolysis to unwinding (1-3). As a result, helicases are key players in a wide variety of DNA and RNA metabolic processes, such as recombination, chromatin remodeling, and DNA transport (4-6). Most recently, helicases have emerged as potential therapeutic targets for diseases ranging from cancer to Gram-positive bacterial infections (7-18). Classified into six superfamilies, superfamily 1 and 2 (SF1 and SF2) helicases are the most similar, sharing up to seven conserved sequence motifs and core RecA-like folds (1-3). Furthermore, SF1 helicases comprise the largest class and can be further subdivided into SF1A and SF1B, based on the direction of helicase translocation along the strand; SF1A helicases progress 3= to 5= and SF1B 5= to 3= (3). Despite their importance, SF1B helicases are still poorly characterized in comparison to SF1A and SF2 helicases, though some recent studies have expanded our knowledge (19-21). SF1B helicases are critical to a diverse range of processes, including DNA repair by human DNA helicase B (22), telomere regulation by Pif1 (23), and conjugative plasmid transfer by F TraI (24).Conjugative plasmid transfer (CPT) mediates the propagation of antibiotic resistance genes and virulence factors within commensal and pathogenic bacteria (25-27) and relies on the helicase domain of a bifunctional protein to facilitate plasmid DNA transfer (24,(28)(29)(30). Early work characteri...

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“…Also a compound that resembles nucleotides (called QU663) was recently reported to be a potent HCV helicase inhibitor that competes with the nucleic acid substrate but not ATP with a Ki of 0.75 µM (Maga et al,,2005) Many groups have reported non-nucleoside based inhibitors of HCV helicase, primarily in the patent literature. These compounds include a piperidine derivative, heterocyclic carboxamide, antracycline antibiotics (Borowski et al, 2002b), paclitaxel, trifluoperazine (Borowski et al, 2002a), and aminophenylbenzimidazole derivatives (Phoon et al, 2001). Many of these compounds intercalate in nucleic acids and likely act via that non-specific mechanism.…”

Section: Small Moleculesmentioning

confidence: 99%

The Hepatitis C Virus NS3 Protein: A Model RNA Helicase and Potential Drug Target

2007

Current Issues in Molecular Biology

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The C-terminal portion of hepatitis C virus (HCV) nonstructural protein 3 (NS3) forms a three domain polypeptide that possesses the ability to travel along RNA or single-stranded DNA (ssDNA) in a 3' to 5' direction. Fueled by ATP hydrolysis, this movement allows the protein to displace complementary strands of DNA or RNA and proteins bound to the nucleic acid. HCV helicase shares two domains common to other motor proteins, one of which appears to rotate upon ATP binding. Several models have been proposed to explain how this conformational change leads to protein movement and RNA unwinding, but no model presently explains all existing experimental data. Compounds recently reported to inhibit HCV helicase, which include numerous small molecules, RNA aptamers and antibodies, will be useful for elucidating the role of a helicase in positive-sense single-stranded RNA virus replication and might serve as templates for the design of novel antiviral drugs.

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Biological evaluation of hepatitis c virus helicase inhibitors

Cited by 81 publications

References 5 publications

RNA helicases in infection and disease

RNA helicases in infection and disease

Unique Helicase Determinants in the Essential Conjugative TraI Factor from Salmonella enterica Serovar Typhimurium Plasmid pCU1

The Hepatitis C Virus NS3 Protein: A Model RNA Helicase and Potential Drug Target

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