CLONING AND SEQUENCE-ANALYSIS OF THE GENES ENCODING DNA-POLYMERASE, GLYCOPROTEIN-B, ICP18.5 AND MAJOR DNA-BINDING PROTEIN OF RAT CYTOMEGALOVIRUS

In all herpesviruses a block of genes is present which is composed of the genes encoding DNA polymerase, glycoprotein B (gB), ICP18.5 and ma jor DNA-binding protein (MDBP), Here we report the cloning and sequenc ing of this gene block from rat cytomegalovirus (RCMV). The gene block spans 13.3 kbp and contains the four genes in the order pol, gB, ICP1 8.5 and MDBP. A similar order of genes has previously been reported fo r human and murine cytomegaloviruses. The pol, gB, ICP18.5 and MDBP ge nes contain open reading frames which have the capacity to encode prot eins of 1120, 984, 893 and 1281 amino acids, respectively. Comparison of the predicted amino acid sequences of the four RCMV proteins with t he corresponding proteins of other herpesviruses revealed a close rela tionship between RCMV and other cytomegaloviruses, which corroborates the usefulness of the RCMV-rat model for studying cytomegalovirus biol ogy.