H. Delius et al., THE GENOMES OF 3 OF 4 NOVEL HPV TYPES, DEFINED BY DIFFERENCES OF THEIR L1 GENES, SHOW HIGH CONSERVATION OF THE E7 GENE AND THE URR, Virology, 240(2), 1998, pp. 359-365
The DNA genomes of four new human papillomaviruses, HPV 75, HPV 76, HP
V 77, and HPV 80, have been cloned, sequenced, and characterized. HPV
75, HPV 76 (both HPV 49-related), and HPV 77 (HPV 29-related) were iso
lated from benign cutaneous warts and HPV 80 (HPV 15-related) from his
tologically normal skin. HPV 77 has also been demonstrated in dysplast
ic warts and squamous cell carcinomas of the skin. The sequence data p
resented in this study led to a proposed modification of the definitio
n of a new HPV type. The high degree of DNA sequence similarity betwee
n the E7 ORF of HPV 77 and HPV 29 (97.7%), as opposed to the E6 (82.8%
) and L1 (85.3%) ORFs, might suggest conservation of a specific functi
on or a possible recombinational event. Only the E6 and L1 ORFs of HPV
75 and HPV 76 have a similarity lower than 90%, whereas the DNA seque
nces of their upstream regulatory regions (URRs) share a similarity of
93%. The E7, E1, and E4 ORFs, as well as the URR of HPV 15 and HPV 80
, share sequence similarities higher than 90%. Such a divergence in th
e similarity between different segments of the virus genomes of closel
y related HPV types has not been noted to date. A detailed comparative
sequence analysis was performed. HPV 75, HPV 76, and HPV 80 revealed
features characteristic of truly cutaneous HPV types, whereas HPV 77 s
hared several characteristics with the mucosal HPV types, some of whic
h may have functional consequences.