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Nucleotide sequence and mutational analysis indicate that two Helicobacter pylori genes encode a P‐type ATPase and a cation‐binding protein associated with copper transport
Author(s) -
Ge Zhongming,
Hiratsuka Koji,
Taylor Diane E.
Publication year - 1995
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1995.tb02224.x
Subject(s) - biology , operon , periplasmic space , nucleic acid sequence , peptide sequence , mutant , homology (biology) , genetics , amino acid , open reading frame , atpase , microbiology and biotechnology , sequence alignment , gene , biochemistry , escherichia coli , enzyme
Summary A 2.7 kb fragment of Helicobacter pylori UA802 chromosomal DNA was cloned and sequenced. Three open reading frames (designated ORF1, oRF2 and ORF3, respectively) were predicted from the DNA sequence, of which ORF1 and ORF2 appeared to be located within the same operon. The deduced 611‐amino‐acid sequence of ORF1, a P‐type ATPase (designated hpCopA), had striking homology (29‐38%) with several bacterial P‐type ATPases and contained the potential functional domains conserved in P‐type ATPases from various sources ranging from bacterial to human. A protein of 66 amino acids (designated hpCopP) encoded by ORF2 shared extensive sequence similarity with MerP, a periplasmic mercuric ion‐transporting protein, and contains the heavy metal‐binding motif. Disruption of ORF1 with a chloramphenicol‐resistance cassette (CAT) rendered the H. pylori mutants more susceptible to cupric ion than their parental strains, whereas there is no significant alternation of susceptibility to Ni 2+ , Cd 2+ and Hg 2+ between the mutants and the parental strains. The results obtained indicate that ORF1 and ORF2 comprise a cation‐transporting system which is associated with copper export out of the H. pylori cells.