[Characteristics of the primary and secondary DNA structure of staphylococcal phage SB-1]

Equilibrium centrifugation, spectral analysis of thermal denaturation and direct chemical determinations showed staphylococcal phage Sb-I DNA to be characterized by a standard set of nitric bases (28.5 mol.2./% G-C). No abnormal bases or other extracomponents were found. From the differential spectral analysis of melting interval it is concluded that G-C pairs are distributed along DNA molecule in a Gauss type. Spectrophotometric and thermodynamic parameters of melting show phage Sv-I DNA to have a typical double-stranded structure. DNA is characterized by enthalpies of conformational transitions of spiral=glome delta H=11.4 cal/g and delta H = 9.7 cal/g for 1 x SSC and 0.1 x SSC diluents, respectively.