Crystal structures of cyanide complexes of P450cam and the oxygenase domain of inducible nitric oxide synthase-structural models of the short-lived oxygen complexes
Fedorov, R., Ghosh, D.K., Schlichting, I.(2003) Arch Biochem Biophys 409: 25-31
- PubMed: 12464241 
- DOI: https://doi.org/10.1016/s0003-9861(02)00555-6
- Primary Citation of Related Structures:  
1N2N, 1O76 - PubMed Abstract: 
The crystal structure of the ternary cyanide complex of P450cam and camphor was determined to 1.8A resolution and found to be identical with the structure of the active oxygen complex [I. Schlichting et al., 2000, Science 287, 1615]. Notably, cyanide binds in a bent mode and induces the active conformation that is characterized by the presence of two water molecules and a flip of the carbonyl of the conserved Asp251. The structure of the ternary complex of cyanide, L-arginine, and the oxygenase domain of inducible nitric oxide synthase was determined to 2.4A resolution. Cyanide binds essentially linearly, interacts with L-Arg, and induces the binding of a water molecule at the active site. This water is positioned by backbone interactions, located 2.8A from the nitrogen atom of cyanide, and could provide a proton required for O-O bond scission in the hydroxylation reaction of nitric oxide synthase.
Organizational Affiliation: 
Abt. Biophysikalische Chemie, Max Planck Institut für Molekulare Physiologie, Otto Hahn Strasse 11, 44227 Dortmund, Germany.