title: Identification of Inhibitors for the DEDDh Family of Exonucleases and a Unique Inhibition Mechanism by Crystal Structure Analysis of CRN-4 Bound with 2-Morpholin-4-ylethanesulfonate (MES).
abstract: The DEDDh family of exonucleases plays essential roles in DNA and RNA metabolism in all kingdoms of life. Several viral and human DEDDh exonucleases can serve as antiviral drug targets due to their critical roles in virus replication. Here using RNase T and CRN-4 as the model systems, we identify potential inhibitors for DEDDh exonucleases. We further show that two of the inhibitors, ATA and PV6R, indeed inhibit the exonuclease activity of the viral protein NP exonuclease of Lassa fever virus in vitro. Moreover, we determine the crystal structure of CRN-4 in complex with MES that reveals a unique inhibition mechanism by inducing the general base His179 to shift out of the active site. Our results not only provide the structural basis for the inhibition mechanism but also suggest potential lead inhibitors for the DEDDh exonucleases that may pave the way for designing nuclease inhibitors for biochemical and biomedical applications.
authors.affiliation: Department of Biological Science and Technology, National Chiao Tung University , Hsinchu 30068, Taiwan, ROC.|Institute of Molecular Biology, Academia Sinica , Taipei 11529, Taiwan, ROC.
authors.forename: Kuan-Wei
authors.initials: KW
authors.lastname: Huang
authors.affiliation: Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University , Taipei 11031, Taiwan.
authors.forename: Kai-Cheng
authors.initials: KC
authors.lastname: Hsu
authors.affiliation: Institute of Molecular Biology, Academia Sinica , Taipei 11529, Taiwan, ROC.|Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica , Nankang, Taipei 11529, Taiwan.|Institute of Bioinformatics and Structural Biology, National Tsing Hua University , 101 Kuang-Fu Road Section 2, Hsinchu 30013, Taiwan.
authors.forename: Lee-Ya
authors.initials: LY
authors.lastname: Chu
authors.affiliation: Department of Biological Science and Technology, National Chiao Tung University , Hsinchu 30068, Taiwan, ROC.|Institute of Bioinformatics and Systems Biology, National Chiao Tung University , Hsinchu, 30050, Taiwan.|Center for Bioinformatics Research, National Chiao Tung University , Hsinchu 30068, Taiwan.
authors.forename: Jinn-Moon
authors.initials: JM
authors.lastname: Yang
authors.affiliation: Institute of Molecular Biology, Academia Sinica , Taipei 11529, Taiwan, ROC.
authors.forename: Hanna S
authors.initials: HS
authors.lastname: Yuan
authors.affiliation: Department of Biological Science and Technology, National Chiao Tung University , Hsinchu 30068, Taiwan, ROC.|Institute of Bioinformatics and Systems Biology, National Chiao Tung University , Hsinchu, 30050, Taiwan.|Institute of Molecular Medicine and Bioengineering, National Chiao Tung University , Hsinchu 30068, Taiwan.
authors.forename: Yu-Yuan
authors.initials: YY
authors.lastname: Hsiao
mesh_terms: D017738:Alkanesulfonic Acids / Q000737:chemistry*; D029742:Caenorhabditis elegans Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D004277:DNA, Single-Stranded / Q000737:chemistry; D004706:Endodeoxyribonucleases / Q000037:antagonists & inhibitors / Q000737:chemistry; D005092:Exonucleases / Q000037:antagonists & inhibitors* / Q000737:chemistry; D005095:Exoribonucleases / Q000037:antagonists & inhibitors / Q000737:chemistry; D007836:Lassa virus / Q000201:enzymology; D062105:Molecular Docking Simulation; D015394:Molecular Structure; D009025:Morpholines / Q000737:chemistry*; D012313:RNA / Q000737:chemistry; D014764:Viral Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry
chemical_list: D017738:Alkanesulfonic Acids; D029742:Caenorhabditis elegans Proteins; D004277:DNA, Single-Stranded; D009025:Morpholines; D014764:Viral Proteins; C004550:2-(N-morpholino)ethanesulfonic acid; D012313:RNA; C534605:CRN-4 protein, C elegans; D004706:Endodeoxyribonucleases; D005092:Exonucleases; D005095:Exoribonucleases; C042081:exoribonuclease T