BKV splice sequences based on analysis of preferred donor and acceptor sites.

We have determined the DNA sequences which correspond to the splicing regions in the transcripts of human papovavirus BKV, an evolutionary variant of SV40. To precisely localize the excision points in the BKV sequence, we have conducted a preliminary analysis of numerous viral and eukaryotic splice site sequences. This analysis suggests that the preferred sequence for the donor site belongs to at least one of four groups: Pu↓GTAxG, Pu↓GTAxxT, Pu↓GTxxGT, Pu↓GTxAG (↓ = the cleavage site). These four groups derive from the two basic sequences, Pu↓GTxxG and Pu↓GTA. An optimal donor site might be: AG↓GTAAGT. The preferred sequence for the acceptor site is of the form PyPyxPyAG↓; no dinucleotide AG occurs within 13 nucleotides prior to the terminal AG of the 3' end of the intervening sequences. As we have found in this study of BKV splice sites, the sequences for the preferred donor and acceptor sites provide predictive value in localizing RNA splice points when the DNA sequence is known.