P1 transduction map spanning the replication terminus of Escherichia coli K12

The region of the E. coli chromosome that contains the replication terminus has not previously been spanned by P1 cotransduction. We have used Tn5, Tn9 and Tn10 transposons inserted in this region as genetic markers, and have constructed a genetic map that extends from fnr (min 29.3) to manA (min 35.7). The relevant transposons that have been mapped in this region and which are described in this report are trg-1::Tn5 (min 31.1), zdc-235::Tn10 (min 32.3), zdd-230::Tn9 (min 33.3), and zde-234::Tn10 (min 34.2). The size of this region as determined by P1 cotransduction is very similar to previous estimates obtained by bacterial conjugation.