Characterization of site-specific mutants of alkylhydroperoxide reductase with dual functionality from Helicobacter pylori.

Alkylhydroperoxide reductase (AhpC) is an abundant and important antioxidant protein present in Helicobacter pylori (HP), a spiral Gram-negative microaerophilic bacterium. By sequence alignment and structure comparison, HP-AhpC was found to be more homologous to human peroxiredoxins (hPrx) than to other eubacterial AhpC proteins. Similar to hPrxI, native HP-AhpC existed as a dimer of single subunit, comprising alpha-helix and beta-sheet domains with low surface hydrophobicity.