related to each other

Computer-assisted analysis of the amino acid se-quences of vaccinia virus proteins containing the purine NTP-binding pattern revealed the seven motifs typical of the DNA (RNA) helicase superfamily lI in the proteins I8R and A18R. Together with the previously described putative helicases D6R and D l l L, the number of putative helicases of this superfamily encoded by the genome of vaccinia virus now reaches four. Aside from the helicase motifs, the sequences of I8R and A18R showed no strong similarity to each other, nor to D6R and D11L. Statistically significant similarity was demonstrated between I8R and the putative RNA helicases involved in pre-mRNA splicing in yeast, PRP2, PRP16 and PRP22, whereas A l8R appeared to be related to the putative helicases encode