title: Methylated bases of Bacillus megaterium KM nucleic acids: comparison with Escherichia coli.
abstract: Parallel studies were performed with methionineless derivatives of Escherichia coli 15 T(-) and Bacillus megaterium KM: T(-). Methylated bases are present in the total cell ribonucleic acid (RNA) of B. megaterium. The level of RNA methylation in E. coli is about 60% greater than that in B. megaterium. Although E. coli deoxyribonucleic acid (DNA) was found to contain 0.12% 5-methylcytosine (5-MC) and 0.24% 6-methylaminopurine (6-MA), methylated bases were not detected in the DNA of B. megaterium. Assuming a molecular weight of 7 x 10(9) daltons for B. megaterium DNA, it was calculated that this organism could not contain more than one molecule of 5-MC or 6-MA per genome, and that possibly no methylated bases were present. Methylated bases were also not detected in the DNA of thymine-starved B. megaterium. Crude extracts of this organism possess RNA methylase activity but no detectable DNA methylase activity.
mesh_terms: D000225:Adenine / Q000032:analysis*; D001410:Bacillus megaterium / Q000032:analysis* / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism; D002247:Carbon Isotopes; D002854:Chromatography, Paper; D003470:Culture Media; D003596:Cytosine / Q000032:analysis*; D004269:DNA, Bacterial / Q000032:analysis*; D004926:Escherichia coli / Q000032:analysis* / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism; D005612:Freeze Drying; D005827:Genetics, Microbial; D008715:Methionine / Q000378:metabolism; D008745:Methylation; D009154:Mutation; D012329:RNA, Bacterial / Q000032:analysis*; D013045:Species Specificity; D013941:Thymine / Q000032:analysis* / Q000378:metabolism; D014166:Transferases / Q000378:metabolism; D014316:Tritium
chemical_list: D002247:Carbon Isotopes; D003470:Culture Media; D004269:DNA, Bacterial; D012329:RNA, Bacterial; D014316:Tritium; D003596:Cytosine; D008715:Methionine; D014166:Transferases; D000225:Adenine; D013941:Thymine