Development of a Genetically Engineered Venezuelan Equine Encephalitis Virus Vaccine
Final rept. 28 Sep 89-30 Sep 90,
CENTERS FOR DISEASE CONTROL FORT COLLINS CO DIV OF VECTOR-BORNE VIRAL DISEASES
Pagination or Media Count:
Genomes of the Trinidad donkey TRD and TC-83 strains of Venezuelan equine encephalitis VEE viruses have been cloned and their nucleotide sequences determined. There are 12 nucleotide differences between the genomes of the TC-83 attenuated virus and its virulent TRD parent strain. One nucleotide substitution and deletion occurred in the 5- and 3- noncoding regions of the TC 83 genome, respectively. A conservative Ser to Thr amino acid substitution was identified in nsP3 and an Ala to Asp change in NsP2. Two silent mutations are present, one each in E1 and E2. Two amino acid substitutions are found in E1, and five amino acid substitutions are in E2. The genome of TRD virus is 11, 444 nucleotides long with 5-noncoding region of 44 nucleotides. The carboxyl- terminal portion of NsP3 contains two peptide segments that are repeated. The open-reading-frame of the nonstructural polypeptide is interrupted by an in- frame opal codon between nsP3 and nsP4, as has been reported for other alphaviruses.
- Medicine and Medical Research