Cloning and sequencing of the hemE gene encoding uroporphyrinogen III decarboxylase (UPD) from Escherichia coli K-12.

Among the photoresistant revertants of the visA-deleted (hemH-deleted) strain of Escherichia coli K-12, three mutants defective in the hemE gene encoding uroporphyrinogen III decarboxylase (UPD) were identified. Using one of the mutants, we cloned and sequenced the hemE of E. coli. We found an open reading frame of 353 codons, which encoded a predicted amino acid (aa) sequence that exhibited a high degree of homology over its entire length to the aa sequence of UPD from humans and other organisms. This hemE was located at 90.3 min near the hupA gene on the linkage map of the E. coli chromosome.