Size of the poly(A) sequences in encephalomyocarditis virus RNA

Poly(A) sequences were demonstrated in the RNA of encephalomyocarditis (EMC) virus by affinity chromatography on poly(U)-Sepharose, treatment with RNases, and determination of the ability of the RNA to prime for reverse transcription. The size of the poly(A) sequences was estimated as 10-20 nucleotides in length by determination of the fraction resistant to pancreatic RNases plus T1 RNases, followed by analysis of electrophoretic mobility on polyacrylamide gels and of the AMP-to-adenosine ratio after alkaline hydrolysis. The poly(A) sequences are located at the 3' end of the RNA as shown by mild digestion by snake venom phosphodiesterase.