title: Nucleic acid sequence of the region of the genome encoding capsid protein VP1 of neurovirulent and attenuated type 3 polioviruses.
abstract: Three closely related strains of poliovirus type 3 have been used to study the molecular basis of attenuation in the currently used Sabin vaccine of this serotype. Plaque-purified derivatives of these strains possess closely similar serological and biochemical properties yet differ markedly in neurovirulence for monkeys. Molecular cloning via an RNA . cDNA method has facilitated comparative nucleotide sequencing. Initial efforts have concentrated on the region of the genome encoding VP1. Only minor structural differences between neurovirulent and attenuated type 3 strains were detected, in contrast to the major differences observed between the vaccine strains of poliovirus type 1 and its virulent precursor P1/Mahoney. These observations suggest that the molecular basis of attenuation of type 3 Sabin vaccine virus does not involve the VP1 polypeptide and, therefore, that mutations conferring the attenuated phenotype probably lie elsewhere in the genome.
mesh_terms: D001483:Base Sequence; D002213:Capsid / Q000235:genetics*; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000302:isolation & purification; D006801:Humans; D017955:Poliovirus / Q000235:genetics* / Q000472:pathogenicity; D011055:Poliovirus Vaccine, Oral; D012367:RNA, Viral / Q000302:isolation & purification; D014613:Vaccines, Attenuated; D014774:Virulence
chemical_list: D004279:DNA, Viral; D011055:Poliovirus Vaccine, Oral; D012367:RNA, Viral; D014613:Vaccines, Attenuated