Organization and Expression of Bacteriophage T7 DNA

Bacteriophage T7 is a virulent bacteriophage that infects Escherichia coli. The seventh of the original set of T bacteriophages (Demerec and Fano 1945), T7 has been the object of considerable genetic and biochemical investigation (for review, see Studier 1972, 1979; Studier et al. 1979; Dunn and Studier 1981, 1983). The T7 virion contains a single molecule of linear, doublestranded DNA, and the nucleotide sequence of the entire 39,936 bp has now been determined (Oakley and Coleman 1977; Dunn and Studier 1981, 1983; Stahl and Zinn 1981). All of the known T7 genes and genetic signals have been located within the nucleotide sequence, and several previously unsuspected genes have been revealed. The genetic organization of T7 DNA and the overall pattern of gene expression during T7 infection can now be understood at the nucleotide level.