Nucleotide sequences of mRNAs encoding Epstein-Barr virus nuclear proteins: a probable transcriptional initiation site.

Abstract
Three cDNA clones of the second Epstein-Barr virus nuclear antigen (EBNA2) mRNA and two of the EBNA1 mRNA were analyzed. Two EBNA2 clones begin 42 bases 39 to a promoter in the Epstein-Barr virus long internal repeat, which is likely to be the EBNA2 promoter. Surprisingly, the first splice creates an AUG at the beginning of the first of two nonoverlapping open reading frames. The second open reading frame encodes EBNA2. Two incomplete EBNA1 mRNA cDNA clones begin with parts of two of the EBNA2 exons and contain two other exons that map 19 and 59 kilobases 39 to the EBNA2 coding domain. The 39 exon of this mRNA encodes EBNA1. A model for regulation of transcription of these RNAs is presented.