HELICOBACTER-PYLORI GENES HPCOPA AND HPCOPP CONSTITUTE A COP OPERON INVOLVED IN COPPER EXPORT

We previously reported that a gene hpcopA isolated from Helicobacter p ylori is associated with copper transport. In the present study, the D NA upstream of the hpcopA was cloned and the nucleotide sequence analy zed. An open reading frame coding for 124 amino acids was predicted, w hich was connected in frame to the hpcopA. The deduced protein sequenc e exhibits striking homology with known copper-transporting P-type ATP ases. Disruption of this ORF renders H. pylori hypersensitive to coppe r present in growth media, indicating that it encodes the N-terminal a mino acid sequence of the hpCopA. protein. Measurement of copper conte nt in the wild-type and hpcopA-disrupted cells showed that the copper content was increased in the mutant cells, further supporting that the previous proposal that the gene hpcopA is involved in copper export. In addition, the cap operon consisting of the genes hpcopA and hpcopP was identified by primer extension and reverse transcription polymeras e chain reaction. Our results indicate that the genes for copper impor t and export are located in separate operons within H. pylori.