COMPARISON OF NUCLEOTIDE AND DEDUCED AMINO-ACID-SEQUENCE OF THE 5' NONCODING REGION AND STRUCTURAL PROTEIN GENES OF THE WILD-TYPE JAPANESE ENCEPHALITIS-VIRUS STRAIN-SA14 AND ITS ATTENUATED VACCINE DERIVATIVES
Hl. Ni et al., COMPARISON OF NUCLEOTIDE AND DEDUCED AMINO-ACID-SEQUENCE OF THE 5' NONCODING REGION AND STRUCTURAL PROTEIN GENES OF THE WILD-TYPE JAPANESE ENCEPHALITIS-VIRUS STRAIN-SA14 AND ITS ATTENUATED VACCINE DERIVATIVES, Journal of General Virology, 75, 1994, pp. 1505-1510
Nucleotide sequences of the 5' non-coding region and the structural pr
otein genes of the live, attenuated Japanese encephalitis vaccine viru
s strains SA14-2-8 and SA14-5-3 and the wild-type parental strain SA14
/USA were determined. SA14-2-8 differed from SA14/USA by 13 nucleotide
s and eight amino acids whereas SA14-5-3 differed from SA14/USA by 15
nucleotides and eight amino acids. A comparison of the 5' noncoding re
gion and amino acid sequences of the structural proteins of these two
attenuated vaccine strains and of vaccine strains SA14-14-2/PHK and SA
14-14-2/PDK with three sequences of their wild-type parent SA14 virus
was performed. This revealed only two common amino acid substitutions
at positions 138 and 176 in the envelope (E) protein. The substitution
at E138 was predicted to cause a change in the secondary structure of
the E protein. These two amino acid substitutions in the E protein ma
y contribute to attenuation of the Japanese encephalitis vaccine virus
es.