FUNCTIONAL-ORGANIZATION OF THE BACTERIOPHAGE PRD1 GENOME

PRD1 is a broad-host-range virus that infects Escherichia coli cells. It has a linear double-stranded DNA genome that replicates by a protei n-primed mechanism. The virus particle is composed of a protein coat e nclosing a lipid membrane. On the basis of this structure, PRD1 is bei ng used as a membrane biosynthesis and structure model. In this invest igation, we constructed the transcription map of the 15-kb-long phage genome. This was achieved by a computer search of putative promoters, which were then tested for activity by primer extension and for the ca pability to promote the synthesis of chloramphenicol acetyltransferase .