[Study of the structure of bacteriophage DD7 by the small angle of dispersion x-ray method]

The method of roentgen small angle dispersion was used for the study of the structure of bacteriophage DD7. According to the results, phage DD7 is a homogeneous icosahedral particle (with the edge of 410-415 A) with a round cylindrical tail (1700-1750 A in length, 110-120 A in diameter). The lineal sizes of the head exceed those determined by electron microscope approximately by 25%. The thickness of the protein coat of the phage is 25-30 A, that is, 2 times less than that of phages Cd and PB-2. This confirms the assumption that the lipid-containing portion of the phage coat is eliminated by centrifugation in cesium chloride density gradient.