Abstract
The metJBLF gene cluster of Escherichia coli K12 is located at 88' on its recombination map. The cytR gene was chosen as the site of insertion in close proximity to this cluster for constructing specialized lambda met transducing phage carrying varying amounts of the metJBLF gene cluster. These transducing phage were constructed for the purpose of determining the structural order of the cluster and to physically characterize the DNA regions surrounding it. Two types of transducing phage were constructed, defective and plaque-forming. The plaque-forming transducing phage were characterized by restriction endonuclease mapping, deletion analysis and enzyme activity determinations within different genetic backgrounds. The results obtained from these analyses enabled the structural ordering of the genes within the met gene cluster as metJBLF. It was also determined that the metB gene can be expressed independently of all other genes within the cluster. The defective transducing phage were characterized in the same manner. The data gained from these phage allowed the positioning of the cytR locus and the met cluster relative to the btuB locus (89'). There are 41.6 Kbp of DNA between these two loci. The arg/ppc deletion (N. Glansdorff, thesis, 1966, Brussels, Germany) was determined to be 22.1 Kbp in length and its counterclockwise terminus lies within 2.2 Kbp of the terminus of metF. The metJBLF gene cluster lies 4.25 Kbp from the cytR locus and 31.8 Kbp from the btuB locus.
Liljestrand, Cheryl An (1983). The structural and transcriptional organization of the metJBLF gene cluster in Escherichia coli K12. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -537955.