The role of surface basic amino acids of dengue virus NS3 helicase in viral RNA replication and enzyme activities.
Structure-based mutagenesis analysis on selected conserved surface basic residues of DENV NS3 helicase was performed using a selectable replicon and recombinant protein. We found a requirement for basic side chains of NS3 residues #225, #268, and #538 to activate viral RNA replication and ensure RNA-stimulated ATPase activity, and a critical role for R560 and R599 residues in maintaining NS3 helicase structure, linked to its biological function and catalytic activity. Three screened NS3 second-site mutations for R225A and R268A/E mutations elevated the functional RNA binding of NS3 helicase and compensated the replication defect of the original NS3 mutant replicons.
Graduate Institute of Life Sciences, National Defense Medical Centre, Taipei, Taiwan.|Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
Pao-Yin
PY
Chiang
Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
Huey-Nan
HN
Wu
D019943:Amino Acid Substitution; D000596:Amino Acids; D003716:Dengue Virus / Q000502:physiology*; D020125:Mutation, Missense; D020365:RNA Helicases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000096:biosynthesis / Q000235:genetics; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014779:Virus Replication / Q000502:physiology*; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
D000596:Amino Acids; D020365:RNA Helicases; D012367:RNA, Viral; D012697:Serine Endopeptidases; D017361:Viral Nonstructural Proteins; C060028:NS3 protein, flavivirus; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
Dengue virus NS3 protein; RTPase/ATPase/unwinding activities; viral RNA replication