Partial sequence analysis of type 1 dengue virus coding for the nonstructural hydrophilic protein NS-3.

A complementary DNA copy of DEN-1 RNA was synthesized using reverse transcriptase and a random primer. The double-stranded DNA copy was cloned at the Sma I site of the pUC13 vector and was used to transform Escherichia coli JM83. Among the transformants selected for characterization by nucleotide sequence analysis, we report here one that codes for a region of nonstructural hydrophilic protein, NS-3. Computer analysis of this sequence (967 bp) showed about 87% conservation at the amino acid level and 79% at the nucleotide level when compared with dengue serotypes 2, 3 and 4 and Japanese encephalitis virus. This suggests an important function which is common to all four serotypes. Comparison of the cloned region with sequences of the above strains also suggested conservation of hydrophobic regions.