Epstein-Barr virus types 1 and 2 have nearly identical LMP-1 transforming genes.

Although variation in the gene encoding the Epstein-Barr virus (EBV) nuclear protein 2 accounts for much of the difference in the transforming activities of the two EBV strain types, divergence in the principal lymphocyte growth-altering gene, LMP-1, has not been previously evaluated. We have now determined the nucleotide sequence of the LMP-1 gene of a type 2 isolate of EBV, AG876. Surprisingly, the AG876 LMP-1 protein is 93% identical to the prototype type 1 EBV strain B95-8, and this is well within the range of variability previously noted among type 1 EBV LMP-1 genes.