Structure of the hepatitis C virus RNA helicase domain.Yao, N., Hesson, T., Cable, M., Hong, Z., Kwong, A.D., Le, H.V., Weber, P.C.
(1997) Nat Struct Biol 4: 463-467
- PubMed: 9187654
- DOI: https://doi.org/10.1038/nsb0697-463
- Primary Citation of Related Structures:
- PubMed Abstract:
Helicases are nucleotide triphosphate (NTP)-dependent enzymes responsible for unwinding duplex DNA and RNA during genomic replication. The 2.1 A resolution structure of the HCV helicase from the positive-stranded RNA hepatitis C virus reveals a molecule with distinct NTPase and RNA binding domains. The structure supports a mechanism of helicase activity involving initial recognition of the requisite 3' single-stranded region on the nucleic acid substrate by a conserved arginine-rich sequence on the RNA binding domain. Comparison of crystallographically independent molecules shows that rotation of the RNA binding domain involves conformational changes within a conserved TATPP sequence and untwisting of an extended antiparallel beta-sheet. Location of the TATPP sequence at the end of an NTPase domain beta-strand structurally homologous to the 'switch region' of many NTP-dependent enzymes offers the possibility that domain rotation is coupled to NTP hydrolysis in the helicase catalytic cycle.
Structural Chemistry and Virology Department, Schering-Plough Research Institute, Kensworth, New Jersey 07033, USA.