Radioimmunologic characterization of RD-114 reverse transcriptase: Evolutionary relatedness of mammalian type C viral pol gene products

The reverse transcriptase of RD-114, an endogenous mammalian type C virus, has been purified and characterized by radioimmunologic techniques. Using radioimmunoprecipitation assays, specific antibodies to reverse transcriptase were detected in the sera of animals naturally or experimentally infected with mammalian type C viruses. Competition radioimmunoassays using the purified enzyme as a probe detected type-specific antigenic determinants of RD-114 reverse transcriptase, as well as group-specific determinants shared with baboon endogenous virus. The pol gene products of all mammalian type C viruses were shown to share interspecies antigenic determinants not detected among functionally analogous reverse transcriptases of other retroviruses. These findings, together with previous immunologic evidence, strongly favor a common progenitor in the evolution of mammalian type C viruses.