新規の多ヘム酵素の立体構造解明

抄録

The 2.8Å crystal structure of the novel multiple-heme enzyme, hydroxylamine oxidoreductase from a nitrifying chemoautotrophic bacterium, Nitrosonnonas europaea, is described. Twenty-four hemes lie in the center bottom of the trimeric molecule, localized in four clusters within each monomer. The heme clusters within the trimer are aligned to form a ring that has inlet and outlet sites. The inlet occupied by the novel heme, heme P460. The structure suggests pathways by which ‘dielectron transfer’ may occur through the precisely arranged hemes.