Structure of peroxiredoxin from the anaerobic hyperthermophilic archaeon Pyrococcus horikoshii

The crystal structure of peroxiredoxin from the anaerobic hyperthermophilic archaeon Pyrococcus horikoshii (PhPrx) was determined at a resolution of 2.25 Å. The overall structure was a ring‐type decamer consisting of five homodimers. Citrate, which was included in the crystallization conditions, was bound to the peroxidatic cysteine of the active site, with two O atoms of the carboxyl group mimicking those of the substrate hydrogen peroxide. PhPrx lacked the C‐terminal tail that forms a 32‐residue extension of the protein in the homologous peroxiredoxin from Aeropyrum pernix (ApPrx).