CODEHOP strategies to identify and molecularly characterize new herpesviruses targeting the DNA polymerase gene. (A) Conserved sequence domains within herpesvirus DNA polymerases. Functional properties of these domains and amino acid (one letter code) motifs present in the domains are indicated. Motifs chosen as targets for the CODEHOP strategy are shown as black boxes. (B) Schematic diagram of the CODEHOP primer positions, the amplification products and their sizes. See Table 1 for primer sequences.