EBNA1 Binding Protein 2 (EBNA1BP2)

EBP2 is a 35-kDa protein that is conserved in a variety of organisms and is predicted to form coiled-coil interactions. The region of EBNA1 that binds EBP2 and generated internal deletion mutants of EBNA1 that are deficient in EBP2 interactions. The ability to bind EBP2 correlates with the ability of EBNA1 to support the long-term maintenance in human cells of a plasmid containing the EBV origin, oriP. An EBNA1 mutant lacking amino acids 325 to 376 was defective for EBP2 binding and long-term oriP plasmid maintenance but supported the transient replication of oriP plasmids at wild-type levels.  EBNA1-EBP2 interaction is important for the stable segregation of EBV episomes during cell division but not for the replication of the episomes.