Crystal structure of quinol-dependent nitric oxide reductase from Geobacillus stearothermophilus.
Matsumoto, Y., Tosha, T., Pisliakov, A.V., Hino, T., Sugimoto, H., Nagano, S., Sugita, Y., Shiro, Y.(2012) Nat Struct Mol Biol 19: 238-245
- PubMed: 22266822 
- DOI: https://doi.org/10.1038/nsmb.2213
- Primary Citation of Related Structures:  
3AYF, 3AYG - PubMed Abstract: 
The structure of quinol-dependent nitric oxide reductase (qNOR) from G. stearothermophilus, which catalyzes the reduction of NO to produce the major ozone-depleting gas N(2)O, has been characterized at 2.5 Å resolution. The overall fold of qNOR is similar to that of cytochrome c-dependent NOR (cNOR), and some structural features that are characteristic of cNOR, such as the calcium binding site and hydrophilic cytochrome c domain, are observed in qNOR, even though it harbors no heme c. In contrast to cNOR, structure-based mutagenesis and molecular dynamics simulation studies of qNOR suggest that a water channel from the cytoplasm can serve as a proton transfer pathway for the catalytic reaction. Further structural comparison of qNOR with cNOR and aerobic and microaerobic respiratory oxidases elucidates their evolutionary relationship and possible functional conversions.
Organizational Affiliation: 
Biometal Science Laboratory, RIKEN SPring-8 Center, Sayo, Hyogo, Japan.