title: [Some properties of 1 P+f bacteriophage for Bacillus brevis var. G.-B and its nucleic acid].
abstract: The 1 P+f phage, a virulent mutant of the moderate P+ phage for Bac. brevis var. G.-B., consists of a hexagonal head (90x90 nm) and a long non-contractile tail (340 nm). This phage is characterized by a relatively long latent period (90-110 min) and a low yield (40-50 particles per cell). The 1P+f phage is quite stable at pH values from 1 to 11, insensitive to osmotic shock, treatment with chloroform and acridine orange. The sensitivity of the phage to thermal treatment and UV-radiation has been studied. The nucleic acid of the P+f phage is double-stranded DNA of AT-type (GC equals 34.5 mole %) which contains 5-methylcytosine (0.18 mole %) and N6-methyladenine (0.32 mole%). The level of methylation of cytosine and adenine residues in DNA of the 1 P+f phage does not depend on the host studied (Bac. brevis, P- and S variants). The specificity of methylation of cytosine residues in the S and P- cells appears to be the same. DNA of the 1 P+f phage strongly differs from DNA of the host in nucleotide composition (GC equals 45.7 mole %). Nevertheless, phage DNA is very similar to DNA from Bac. subtilis in the character of pyrimidine distribution (the amount of different pyrimidine isopliths). This may testify to a somewhat common character of the nucleotide sequence organization in DNA of the phage and its host.
mesh_terms: D001407:Bacillus / Q000378:metabolism* / Q000648:ultrastructure; D001435:Bacteriophages / Q000032:analysis / Q000378:metabolism / Q000648:ultrastructure*; D004261:DNA Replication; D004269:DNA, Bacterial / Q000032:analysis; D004279:DNA, Viral / Q000378:metabolism*; D008854:Microscopy, Electron; D013045:Species Specificity; D013696:Temperature; D014779:Virus Replication
chemical_list: D004269:DNA, Bacterial; D004279:DNA, Viral
vernacular_title: Nekotorye svoĭstva bakteriofaga 1 P+f Bacillus brevis var. G.-B. i ego nukleinovoĭ kisloty