The primary sequence of rhesus monkey rhadinovirus isolate 26-95: Sequencesimilarities to Kaposi's sarcoma-associated herpesvirus and rhesus monkey rhadinovirus isolate 17577

The primary sequence of the long unique region L-DNA (L for low GC) of rhes us monkey rhadinovirus (RRV) isolate 26-95 was determined. The L-DNA consis ts of 130,733 bp that contain 84 open reading frames (ORFs), The overall or ganization of the RRV26-95 genome was found to be very similar to that of h uman Kaposi sarcoma-associated herpesvirus (KSHV). BLAST search analysis re vealed that in almost all cases RRV26-95 coding sequences have a greater de gree of similarity to corresponding KSHV sequences than to other herpesviru ses. Ail of the ORFs present in KSHV have at least one homologue in RRV26-9 5 except K3 and K5 (bovine herpesvirus-4 immediate-early protein homologues ), K7 (nut-1), and K12 (Kaposin), RRV26-95 contains one MIP-I and eight int erferon regulatory factor (vIRF) homologues compared to three MIP-1 and fou r vIRF homologues in KSHV, All homologues are correspondingly located in KS HV and RRV with the exception of dihydrofolate reductase (DHFR). DHFR is co rrespondingly located near the left end of the genome in RRV26-95 and herpe svirus saimiri (RVS), but in KSHV the DHFR gene is displaced 16,069 nucleot ides in a rightward direction in the genome. DHFR is also unusual in that t he RRV26-95 DHFR more closely resembles WS DHFR (74% similarity) than KSHV DHFR (55% similarity). Of the 84 ORFs in RRV26-95, 83 contain sequences sim ilar to the recently determined sequences of the independent RRV isolate 17 577, RRV26-95 and RRV17577 sequences differ in that ORF 67.5 sequences cont ained in RRV26-95: were not found in RRV17577, In addition, ORF 4 is signif icantly shorter in RRV26-95 than was reported for RRV17577 (395 versus 645 amino acids). Only four of the corresponding ORFs between RRV26-95 and RRV1 7577 exhibited less than 95% sequence identity: glycoproteins Il and L, ura cil DNA glucosidase, and a tegument protein (ORF 67). Both RRV26-95 and RRV 17577 have unique ORFs between positions 21444 to 21752 and 110910 to 11489 9 in a rightward direction and from positions 116524 to 111082 in a leftwar d direction that are not found in KSHV, Our analysis indicates that RRV26-9 5 and RRV17577 are clearly independent isolates of the same virus species a nd that both are closely related in structural organization and overall seq uence to KSHV. The availability of detailed sequence information, the abili ty to grow RRV lytically in cell culture, and the ability to infect monkeys experimentally with RRV will facilitate the construction of mutant strains of virus for evaluating the contribution of individual genes to biological properties.