Novel non-heme iron center of nitrile hydratase with a claw setting of oxygen atoms.
Nagashima, S., Nakasako, M., Dohmae, N., Tsujimura, M., Takio, K., Odaka, M., Yohda, M., Kamiya, N., Endo, I.(1998) Nat Struct Biol 5: 347-351
- PubMed: 9586994 
- DOI: https://doi.org/10.1038/nsb0598-347
- Primary Citation of Related Structures:  
2AHJ - PubMed Abstract: 
The iron-containing nitrile hydratase (NHase) is a photoreactive enzyme that is inactivated in the dark because of persistent association with NO and activated by photo-dissociation of NO. The crystal structure at 1.7 A resolution and mass spectrometry revealed the structure of the non-heme iron catalytic center in the nitrosylated state. Two Cys residues coordinated to the iron were post-translationally modified to Cys-sulfenic and -sulfinic acids. Together with another oxygen atom of the Ser ligand, these modifications induced a claw setting of oxygen atoms capturing an NO molecule. This unprecedented structure is likely to enable the photo-regulation of NHase and will provide an excellent model for designing photo-controllable chelate complexes and, ultimately, proteins.