Epstein-Barr virus nuclear antigen (EBNA): size polymorphism of EBNA 1.

The mol. wt. of the polymorphic Epstein-Barr virus (EBV) nuclear antigen (EBNA) molecule (EBNA 1) encoded by the BamHI K fragment of the EBV DNA has been determined in 14 EBV-carrying lymphoblastoid and Burkitt's lymphoma cell lines. There is no obvious correlation between the size of this polypeptide and any properties of the cells from which it is derived, other than those related to the strain of transforming virus. We confirm that the polymorphic region of this molecule is the glycine-alanine copolymer encoded by the third internal repeat of the EBV genome (IR3) and we consider the significance of this domain.