title: Self-association and mapping of the interaction domain of hepatitis E virus ORF3 protein.
abstract: Hepatitis E virus (HEV) is a major human pathogen in the developing world. In the absence of an in vitro culture system, very little information on the basic biology of the virus exists. A small protein (approximately 13.5 kDa) of unknown function, pORF3, is encoded by the third open reading frame of HEV. The N-terminal region of pORF3 is associated with the cytoskeleton using one of its hydrophobic domains. The C-terminal half of pORF3 is rich in proline residues and contains a putative src homology 3 (SH3) binding domain and a mitogen-activated protein kinase phosphorylation site. In this study, we demonstrate that pORF3 can homodimerize in vivo, using the yeast two-hybrid system. We have isolated a 43-amino-acid interaction domain of pORF3 which is capable of self-association in vivo and in vitro. The overlap of the dimerization domain with the SH3 binding and phosphorylation domains suggests that pORF3 may have a dimerization-dependent regulatory role to play in the signal transduction pathway.
authors.affiliation: Virology Group, International Centre for Genetic Engineering & Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.
authors.forename: S
authors.initials: S
authors.lastname: Tyagi
authors.forename: S
authors.initials: S
authors.lastname: Jameel
authors.forename: S K
authors.initials: SK
authors.lastname: Lal
mesh_terms: D019281:Dimerization; D016752:Hepatitis E virus / Q000737:chemistry* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D016366:Open Reading Frames; D020798:Two-Hybrid System Techniques; D014764:Viral Proteins / Q000737:chemistry* / Q000378:metabolism*
chemical_list: C400973:ORF3 protein, Hepatitis E virus; D014764:Viral Proteins