OVEREXPRESSION, PURIFICATION, AND CRYSTALLIZATION OF THE DNA-BINDING AND DIMERIZATION DOMAINS OF THE EPSTEIN-BARR-VIRUS NUCLEAR ANTIGEN-1

The Epstein-Barr virus nuclear antigen (EBNA) 1 binds to and activates DNA replication from the latent origin of Epstein-Barr virus. Six different fragments of EBNA1 that retain DNA binding activity were expressed in bacteria, purified, and crystallized. Two fragments, EBNA(470-619) and EBNA(470-607), formed well ordered crystals that diffracted beyond 2.5-Angstrom resolution. Two different EBNA(470-619) crystals were grown from sodium formate, pH 6-6.5. One crystal belonged to the trigonal space group 3 with unit cell dimensions a = b = 86.5 Angstrom and c = 31.8 Angstrom and with two molecules in the asymmetric unit. The other crystal, which appeared only twice and was likely related to the P3 crystal form, belonged to the trigonal space group P312 with cell dimensions a = b = 86.7 Angstrom and c = 31.8 Angstrom. Crystals of EBNA(470-607) were grown by lowering the salt concentration to 0-100 mM NaCl at pH 6.0. These crystals belonged to the orthorhombic space group P2(1)2(1)2(1) and had cell dimensions a = 59 Angstrom, b = 66.9 Angstrom, and c = 69.8 Angstrom with two molecules in the asymmetric unit.