A. Bochkarev et al., CRYSTAL-STRUCTURE OF THE DNA-BINDING DOMAIN OF THE EPSTEIN-BARR-VIRUSORIGIN-BINDING PROTEIN, EBNA1, BOUND TO DNA, Cell, 84(5), 1996, pp. 791-800
The Epstein-Barr virus nuclear antigen 1 (EBNA1) protein binds to and
activates DNA replication from oriP, the latent origin of DNA replicat
ion in Epstein-Barr virus. The crystal structure of the DNA-binding do
main of EBNA1 bound to an 18 bp binding site was solved at 2.4 Angstro
m resolution. EBNA1 comprises two domains, a flanking and a core domai
n. The flanking domain, which includes a helix that projects into the
major groove and an extended chain that travels along the minor groove
, makes all of the sequence-determining contacts with the DNA. The cor
e domain, which is structurally homologous to the complete DNA-binding
domain of the bovine papilloma virus E2 protein, makes no direct cont
acts with the DNA bases. A model for origin unwinding is proposed that
incorporates the known biochemical and structural features of the EBN
A1-origin interaction.