FIG. 11.

Comparison of C-terminal sequences of VP2/VP3 among polyomaviruses. JCV has a unique sequence in the C-terminal region of VP2/VP3. Compared with the BK virus (BKV) and SV40 sequences, eight amino acids are absent between two clusters that are rich in basic amino acids (cluster 1 and cluster 2) in the JCV sequence. Compared with the PyV sequence, an additional 20 amino acids are present in the C terminus in the JCV sequence. Functional domains (a to c) that were shown to be important for virion production are underlined. In PyV and SV40, a region important for the interaction with VP1 lies upstream of the region shown (9, 21), and it has also been reported for the C terminus of the SV40 sequence (20).