Characterization of Bacteriophage S13 su N15 Single-Strand and Replicative-Form Deoxyribonucleic Acid

Abstract

The deoxyribonucleic acid (DNA) of bacteriophage S13 was shown to be singlestranded by the criteria of reactivity with formaldehyde, dependence of optical density on ionic strength, broad temperature-absorbance profile, and lack of molar equivalence of the purine and pyrimidine bases. The DNA has a molecular weight of 1.8 X 106 daltons, an S2 of 24.6 in SSC (0.15 M NaCl plus 0.015 M sodium citrate), and a buoyant density of 1.726 g/cc in CsCl. Electron microscopy showed the molecule to be circular. S13 replicative-form DNA was shown to be a doublestranded, circular molecule with a molecular weight of 3.5 x 106 daltons, an S, of 20.7 in SSC, and a buoyant density in CsCl of 1.710 g/cc. The finding that S13 DNA is slightly more pyrimidine-rich than 4X174 DNA but is indistinguishable by all other parameters supports the close genetic relationship between the two bacteriophages.

Nucleotide clusters in deoxyribonucleic acids. XI. Comparison of the sequences of the large pyrimidine oligonucleotides of bacteriophages S13 and φX174 deoxyribonucleic acids

“…Out of 14 oligonucleotide sequences from SI3 DNA (120 bases) at least ten are identical with sequences of oligonucleotides from 0X174 DNA (92 bases) and two are closely related (17 bases), the only difference being a single thymine to cytosine transition in each sequence (a total of 107 identical bases). The pyrimidine oligonucleotides of each phage J_he small icosahedral bacteriophages S13 and 0X174 both contain single-stranded circular DNAs (Tessman, 1959;Sinsheimer, 1959;Fiers and Sinsheimer, 1962;Spencer et al, 1972) which are almost identical in size and physical characteristics. The phages are serologically related (Zahler, 1958), the number of genes the same and the size of the cistrons similar (Benbow et al, 1971; Baker and Tessman, 1967;Tessman, 1965) as is the pattern of phagecoded proteins separated on sodium dodecyl sulfate polyacrylamide gels (Jeng et al, 1970;Godson, 1973).…”

Nucleotide clusters in deoxyribonucleic acids. IX. Pyrimidine oligonucleotides of mouse L-cell satellite deoxyribonucleic acid and main-band deoxyribonucleic acid

“…Base Ratio Analyses. These were performed as described previously (Spencer et al, 1972), except that Cerenkov radiation was used for determination of radioactivity as described above. replicative-form DNA (arrows) was added to the preparation as marker.…”