NUCLEOTIDE-SEQUENCE COMPARISONS OF THE FUSION PROTEIN GENE FROM VIRULENT AND ATTENUATED STRAINS OF RINDERPEST VIRUS

We have cloned and sequenced the entire fusion (F) protein gene of the RBOK vaccine strain of rinderpest virus and the coding regions for th e F genes of two mild field isolates of the virus from Africa. Analysi s of the nucleotide and the predicted amino acid sequences showed that the vaccine virus was more than 99% identical in the protein coding r egion of the virulent Kabete O strain from which it was derived, where as the field isolates differed by 10 to 12% from each other and from t he vaccine strain. No changes were found in the F protein which could explain attenuation of the vaccine; however, each of the mild field is olated had amino acid changes in important functional areas which may be related to their attenuated phenotype.