Essential genes in the metB-malB region of Escherichia coli K-12

We isolated 25 independent mutants that are deficient in essential genes located in the metB-malB region of the Escherichia coli chromosome. The mutations were mapped within this region by using several F' factors and were also classified into 11 cistrons by complementation testing. There is clustering of mutations in essential genes within the metB-malB region.