IDENTIFICATION AND ANALYSIS OF THE RPOS-DEPENDENT PROMOTER OF KATE, ENCODING CATALASE HPII IN ESCHERICHIA-COLI

The rpoS gene of Escherichia coli encodes an alternative sigma factor of RNA polymerase sigma(38) (or sigma(S)) that is required for transcr iption of katE encoding catalase HPII. The transcription start site of the single katE transcript identified by ribonuclease protection has been determined by primer extension analysis to be either 53 or 54 bp (depending on the strain used) upstream of the open reading frame. A s eries of promoter fragments were constructed and fused to lacZ to conf irm the start site location. A -10 sequence similar to that found in o ther sigma(70) and sigma(38)-dependent E. coli promoters was identifie d 8 or 7 bp upstream of the start site but a sigma(70)-dependent - 35 sequence was not evident.