The Structure of Some Bacteriophages Associated with Male Strains of Escherichia coli

Abstract

SUMMARY: The structure of filamentous phages and RNA-containing phages, both specific for male strains of Escherichia coli, is described in detail. The RNA phages are probably in the form of icosahedra comprising 92 morphological sub-units. The filamentous type consists of a protein coat containing a nucleic acid core which is visible in negative stained preparations. A new morphological type of coliphage isolated on a male strain of E. coli is described and the manner in which the tail is attached to the head is shown in electron micrographs. Two temperate phages from male strains are studied in detail; their head sub-units are shown to number 325 and are arranged in the form of an octahedron.