Defective interfering particles of poliovirus. II. Nature of the defect.

摘要: Abstract Poliovirus defective, interfering particles in which about 15% of the standard viral RNA is deleted have been described (Cole et al., 1971). Stocks DI ‡ more than 99% free poliovirus were prepared by centrifugation mixed preparations CsCl gradients. Using purified particles, it was found that can carry out most functions including inhibition cellular macromolecular synthesis, production and virus-specific protein. Neither kinetics nor extent or protein synthesis differed between particle-infected cells virus-infected cells. Newly made virions, capsid proteins, precursor (NCVP 1) totally absent All other proteins present. DI-infected briefly labeled with amino acids also contained a new polypeptide, DI-P, apparently residual fragment NCVP 1 encoded genome. It very unstable, being rapidly degraded to acid-soluble fragments. When cleavage inhibited acid analogs, precursors generated. Those should had molecular weights 30,000 40,000 daltons lower This amount genome per cent sequence not represented RNA. therefore appear be deletion mutants lacking encoding one-third precursor. Whether internal terminal remains determined.