The S13 Genome

Abstract

Bacteriophage S13, one of the isometric phages, was first described by Burnet (1927) as one of a series of phages isolated from Salmonella cultures; these phages were given the prefix S followed by arabic numerals. Soon after its discovery S13 was found to have anomalous properties in comparison with the other phages. For example, it was shown to migrate to the cathode in an electric field, and this electrical behavior was strikingly affected by changes in pH (Burnet and McKie 1930). It was relatively stable to reducing dyes and diffused much more rapidly than other phages. The latter result led to the speculation that S13 was smaller than most other phages (Burnet and McKie 1930). Evidence to support this hypothesis came from early centrifugal studies by Elford (1936), and an estimate was made of its size as 15 to 17 nm—a figure in agreement with results from previous ultrafiltration analyses (Elford and Andrewes 1932). Subsequent studies concentrated mainly on the action of various compounds on S13 (S13 having been chosen as a test phage because of its small size). One study revealed the unusual result that, unlike other phages, when S13 was irradiated by ultraviolet light it failed to kill its host (Mills 1955).

In 1958, Zahler published a comparison of some of the biological properties of S13 and the more recently discovered ϕX174; a close serological relationship between the two phages was found. In 1959, I. Tessman showed by ³²P-decay studies that the DNA of phage S13 is...