On the structure of the deo operon of Escherichia coli

Abstract

A characterization of a specialized transducing λ phage for the deo operon (λddeo), and some composite colEl-deo plasmids is given in this paper. This includes localization of the RSmaI, RHindIII, RBamI, and REcoRI sensitive sites. The deo genes have been localized by construction of composite colEl-deo plasmids. Using the DNA fragments, obtained by digestion with REcoRI and RHindIII, respectively, as templates in an in vitro protein synthesizing system, it has been possible to give the direction of transcription and the exact location of the deo genes, relative to the endonuclease sites. Furthermore, the cytO,P and deoO,P regions have been mapped relative to the structural genes. Supercoiled colEl-deo DNA has been used as template in the in vitro system; this DNA gives essentially the same results as the endonuclease-fragmented DNA. The use of the different types of templates is discussed.