2N2J: Solution structure of the EBNA-2 N-terminal Dimerization (END) domain from the Epstein-barr virus

Citation:
Abstract
Epstein-Barr virus (EBV) is a gamma-herpesvirus that may cause infectious mononucleosis in young adults. In addition, epidemiological and molecular evidence links EBV to the pathogenesis of lymphoid and epithelial malignancies. EBV has the unique ability to transform resting B cells into permanently proliferating, latently infected lymphoblastoid cell lines. Epstein-Barr virus nuclear antigen 2 (EBNA-2) is a key regulator of viral and cellular gene expression for this transformation process. The N-terminal region of EBNA-2 comprising residues 1-58 appears to mediate multiple molecular functions including self-association and transactivation. However, it remains to be determined if the N-terminus of EBNA-2 directly provides these functions or if these activities merely depend on the dimerization involving the N-terminal domain. To address this issue, we determined the three-dimensional structure of the EBNA-2 N-terminal dimerization (END) domain by heteronuclear NMR-spectroscopy. The END domain monomer comprises a small fold of four beta-strands and an alpha-helix which form a parallel dimer by interaction of two beta-strands from each protomer. A structure-guided mutational analysis showed that hydrophobic residues in the dimer interface are required for self-association in vitro. Importantly, these interface mutants also displayed severely impaired self-association and transactivation in vivo. Moreover, mutations of solvent-exposed residues or deletion of the alpha-helix do not impair dimerization but strongly affect the functional activity, suggesting that the EBNA-2 dimer presents a surface that mediates functionally important intra- and/or intermolecular interactions. Our study shows that the END domain is a novel dimerization fold that is essential for functional activity. Since this specific fold is a unique feature of EBNA-2 it might provide a novel target for anti-viral therapeutics.
PDB ID: 2N2JDownload
MMDB ID: 129853
PDB Deposition Date: 2015/5/9
Updated in MMDB: 2015/06
Experimental Method:
solution nmr
Source Organism:
Similar Structures:
Biological Unit for 2N2J: dimeric; determined by author and by software (PISA)
Molecular Components in 2N2J
Label Count Molecule
Proteins (2 molecules)
2
Epstein-barr Nuclear Antigen 2(Gene symbol: EBNA-2)
Molecule annotation
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