TABLE 1.

Structural organization of HCV E2 ectodomaina

90% Consensus sequence domainH77 domainIdentificationExposurebSecondary structure(s)cFunctiond
384-406384-405HVR1Exposedα
413-431412-430HCR1BuriedβCD81 binding site
474-485473-482HVR2ExposedCD81 binding site
486-523483-520HCR2BuriedβCD81 binding site
552-568549-565HCR3Buried
575-587572-578HVR3Exposed
590-632581-623HCR4Buriedβ
692-710683-701HCR5Buriedα/βHeterodimerization domain
  • a A model of E2 was generated based on present knowledge of E2 function and computational analyses. Numbers indicate the positions of the E2 residues that delineate the boundaries of hypervariable and hyperconserved structural domains in the 90% consensus sequence and the H77 isolate. The 90% consensus sequence is based on all E2 sequences in the HCV database, regardless of genotype.

  • b Exposure indicates whether these domains are predicted to be exposed on the protein surface or buried.

  • c α or β indicates whether these domains are predicted to be characterized by alpha-helices or beta-sheets, respectively.

  • d Data are based on functional analyses reported in the literature.