The 2.8 A structure of hydroxylamine oxidoreductase from a nitrifying chemoautotrophic bacterium, Nitrosomonas europaea.
Igarashi, N., Moriyama, H., Fujiwara, T., Fukumori, Y., Tanaka, N.(1997) Nat Struct Biol 4: 276-284
- PubMed: 9095195 
- DOI: https://doi.org/10.1038/nsb0497-276
- Primary Citation of Related Structures:  
1FGJ - PubMed Abstract: 
The 2.8 A crystal structure of hydroxylamine oxidoreductase of a nitrifying chemoautotrophic bacterium, Nitrosomonas europaea, is described. Twenty-four haems lie in the centre bottom of the trimeric molecule, localized in four clusters within each monomer. The haem clusters within the trimer are aligned to form a ring that has inlet and outlet sites. The inlet is occupied by a novel haem, P460, and there are two possible outlet sites per monomer formed by paired haems lying within a cavity or cleft on the protein surface. The structure suggests pathways by which electron transfer may occur through the precisely arranged haems and provides a framework for the interpretation of previous and future biochemical and genetic observations.
Organizational Affiliation: 
Department of Life Science, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan.