Substrate complexes of hepatitis C virus RNA polymerase (HC-J4): structural evidence for nucleotide import and de-novo initiation.
Several crystal structures of the hepatitis C virus NS5B protein (genotype-1b, strain J4) complexed with metal ions, single-stranded RNA or nucleoside-triphosphates have been determined. These complexes illustrate how conserved amino acid side-chains, together with essential structural features within the active site, control nucleotide binding and likely mediate de-novo initiation. The incoming nucleotide interacts with several basic residues from an extension on the NS5B fingers domain, a beta-hairpin from the NS5B thumb domain and the C-terminal arm. The modular, bi-partite fingers domain carries a long binding groove which guides the template towards the catalytic site. The apo-polymerase structure provides unprecedented insights into potential non-nucleoside inhibitor binding sites located between palm and thumb near motif E, which is unique to RNA polymerases and reverse transcriptases.
O'Farrell
Damien
D
Astbury Centre of Structural Molecular Biology, School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
Trowbridge
Rachel
R
Rowlands
David
D
Jäger
Joachim
J
D001665:Binding Sites; D001692:Biological Transport / Q000502:physiology; D018360:Crystallography, X-Ray; D016174:Hepacivirus / Q000201:enzymology / Q000235:genetics; D008958:Models, Molecular; D015394:Molecular Structure; D009711:Nucleotides / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012324:RNA-Dependent RNA Polymerase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013696:Temperature; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D009711:Nucleotides; D011994:Recombinant Proteins; D017361:Viral Nonstructural Proteins; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase