title: [Defective bacteriophage MS2 particles containing specific RNA FRAGMENTS].
abstract: Two types of MS2 particle are revealed when phage lysates are banded in CsCl density gradient. The lower band contain normal phage particles with a density of 1.46 g/cm3. The upper band with a density of 1.44 g/cm3 containes uninfective incomplete MS2 particles. Both phage types reveal no abnormalities in the content of the coat protein and A-protein. They are nearly identical in RNA content. RNA in the normal buoyant density phage particles is native. RNA in the defective particles consists of three specific fragments with molecular weights 6.5-10(5), 5.5-10(5) and 4.4-10(5) and molar ratios 5:4:9 respectively. THE 5'-TERMINAL ANALYSIS OF RNA from defective MS2 particles reveals the presence of native pppGp. THE 3'-TERMINAL ANALYSIS OF THE INDIVIDUAL RNA fragments reveals the presence of adenosine only in the shortest fragment. RNA fragmentation in defective particles can be explained by the action of intracellular RNAses on the unprotected regions on RNA chain in structurally incomplete virions.
mesh_terms: D001435:Bacteriophages / Q000378:metabolism*; D001483:Base Sequence; D008970:Molecular Weight; D009154:Mutation; D011549:Pseudomonas / Q000378:metabolism*; D012367:RNA, Viral / Q000378:metabolism*; D012265:Ribonucleotides / Q000032:analysis
chemical_list: D012367:RNA, Viral; D012265:Ribonucleotides
vernacular_title: Defektnye chastitsy bakter-ofaga MS2, soderzhashchis spetsificheskie fragmenty RNK