Variability at the 5' ends of two plant viruses.

Adenosine Triphosphate Carbon Dioxide/metabolism Carbon Isotopes Centrifugation, Density Gradient Chromatography, DEAE-Cellulose Chromatography, Paper Electrophoresis Electrophoresis, Paper Isotope Labeling Nucleotides/analysis Phosphoric Diester Hydrolases Phosphoric Monoester Hydrolases Phosphorus Isotopes Phosphotransferases Plant Viruses/analysis Plants/metabolism Polynucleotides/isolation & purification RNA, Viral/biosynthesis Ribonucleases Ribonucleosides/metabolism Tobacco Mosaic Virus/analysis Tritium

Carbon Isotopes Nucleotides Phosphorus Isotopes Polynucleotides RNA, Viral Ribonucleosides Tritium Carbon Dioxide Adenosine Triphosphate Phosphotransferases Ribonucleases Phosphoric Monoester Hydrolases Phosphoric Diester Hydrolases