Figure 2.

Location and transcription of the Epstein-Barr virus (EBV) latent genes on the double stranded viral DNA episome. The large solid arrows represent coding exons for each of the latent proteins and the direction in which they are transcribed. EBNA-LP is transcribed from variable numbers of repetitive exons in the BamHI W fragments. Latent membrane protein 2 (LMP2) is composed of multiple exons located either side of the terminal repeat (TR) region, which is formed during the circularisation of the linear DNA to produce the viral episome. The open arrows represent the highly transcribed non-polyadenylated RNAs, EBER1 and EBER2, which are a consistent feature of latent EBV infection. The outer long arrowed line represents EBV transcription in latency type III, where all the EBNAs are transcribed from either the Cp or Wp promoter; the different EBNAs are encoded by individual mRNAs generated by differential splicing of the same long primary transcript. The inner shorter arrowed line represents the EBNA1 transcript originating from the Qp promoter located in the BamHI Q region; this is transcribed in latency types I and II. EBNA, EBV encoded nuclear antigen; LP, leader proteins.