Biochemical Studies of Bacterial Sporulation and Germination: IX. Ribonucleic Acid and Deoxyribonucleic Acid Polymerases in Nuclear Fractions of Vegetative Cells and Spores of Bacillus Megaterium

Abstract

Abstract Spores of Bacillus megaterium, opened by lysozyme, released an inner globular mass which was visible by phase contrast microscopy. Ruptured spores were observed, by whole mount electron microscopy, to be connected by thin filaments which could be removed by deoxyribonuclease, whereas the globular mass was relatively insensitive to this treatment. A nuclear fraction, isolated from cells and spores by differential sedimentation, contained most of the DNA as well as the DNA and RNA polymerases but relatively little RNA or protein. The polymerases resemble other bacterial polymerases except for template dependence. Only after DNase treatment did the RNA polymerase, previously in a tight complex with DNA, show a requirement for DNA or polyuridylate. The DNA polymerase responded to exogenous template, even in the nuclear fraction. The nuclear fraction isolated from spores was virtually indistinguishable from that obtained from growing vegetative cells. However, the amounts of protein, RNA, and DNA per cell did differ in the several stages of growth and sporulation.