title: Virus-like particles in an estranuclear mutant of Neurospora crassa.
abstract: A particulate fraction not present in wild-type cells has been isolated from the cytoplasm and from lysed mitochondria of the respiratory-deficient extranuclear mutant "abnormal-1" of Neurospora crassa. The particles have a density between 1.13 and 1.2 g/ml. They appear in thin sections after OsO(4) fixation as virus-like polymorphic vesicles containing an electron-dense nucleoid of 120-170 nm in diameter. The central core is surrounded by one or two "unit membrane" envelopes of 100 A thickness. The particles contain a single-stranded 33S RNA that is converted to 7-9S RNA by heat treatment in the presence of sodium dodecyl sulfate and that differs in its base composition from mitochondrial and cytoplasmic ribosomal RNA. They contain 7% phospholipids rich in phosphatidylethanolamine and two major proteins, a lipoprotein of molecular weight 15,000 and a glycoprotein of molecular weight 95,000. It is suggested that these virus-like particles originate within mitochondria.
mesh_terms: D002499:Centrifugation, Density Gradient; D002850:Chromatography, Gel; D003593:Cytoplasm / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D008854:Microscopy, Electron; D008928:Mitochondria / Q000032:analysis; D008970:Molecular Weight; D009154:Mutation; D009491:Neurospora; D009492:Neurospora crassa / Q000032:analysis / Q000254:growth & development; D010743:Phospholipids / Q000032:analysis; D011506:Proteins / Q000032:analysis; D012313:RNA / Q000302:isolation & purification; D012328:RNA Viruses / Q000302:isolation & purification*; D012367:RNA, Viral / Q000032:analysis / Q000302:isolation & purification; D012270:Ribosomes / Q000032:analysis
chemical_list: D010743:Phospholipids; D011506:Proteins; D012367:RNA, Viral; D012313:RNA