[Electron microscopic structure of Erwinia carotovora moderate phage 59 and its DNA]

Electron microscopic examinations showed the moderate phage 59 Erwinia carotovora to consist of a head of icosahedral shape 50.0+/- +/-2.5 nm in diameter, a noncontractile process 150.0+/-3.5 nm in length and 8.2+/-1.0 nm in diameter with a basal plate of 20.0+/-1,5 nm. The head of the virion of 45.9 X 10(3) nm3 in volume is formed by 812 morphological subunits about 3.0 nm in diameter; the number of structural subunits is 4860 on the basis of triangulation number (81). The process of the virus is cross-striated, the pattern being formed by 35+/-1 rows (43+/-5 A) of subunits 3.0 nm in diameter. The total number of subunits in the process is 210+/-6. DNA of the virus under study has a trend of ring formation. Its modal length is 14.61+/-0.53 micron corresponding to a molecular weight of 28.66+/-1.04 X 10(6) daltons. The volume of DNA molecule is 45.9 X X 10(3) nm3, indicating that a portion of phage DNA is in the virion, probably in denaturated state. An electron microscopic model of the organization of the virus under study is proposed.