The Morphogenesis of Bacteriophage Lambda III. Identification of Genes Specifying Morphogenetic Proteins

Abstract

It has been well established that there are at least 18 genes concerned with λ morphogenesis. Seven of them control synthesis of the phage head and DNA maturation, and are situated at the extreme left end of the genetic map. To the right of them lie 11 contiguous genes that control the synthesis of the phage tail (Weigle, 1966; Dove, 1966; Parkinson, 1968: Mount et al., 1968). It is known from electron microscopic observations that the phage particle consists of 4 major structures: the head, the tail, the tail fiber and the core of the head (Karamata et al., 1962; Eiserling and Boy de la Tour, 1965; Kaiser, 1966; Mount et al., 1968; Kemp et al., 1968). Since at least 8 sub-units of different electrophoretic mobilities are observed in extracts of the particles, additional proteins must also be present (Buchwald et al., 1970a; Casjens et al., 1970).

Analysis of the proteins of phage particles and of lysates of specific mutants has allowed the specification of some of the products of morphogenetic genes. Thus it has been shown that gene E codes for the main structural component of the head and gene V for the main structural component of the tail (Buchwald et al., 1970a; Casjens et al., 1970).

The function of most of the other genes in the left arm of the genetic map is not well understood, except that U seems to control the length of the tail of the particle (Mount et al., 1968), and J codes for...