Download MendeleyStructural evidence for direct hydride transfer from NADH to cytochrome P450nor
Oshima, R., Fushinobu, S., Su, F., Zhang, L., Takaya, N., Shoun, H.(2004) J Mol Biol 342: 207-217
- PubMed: 15313618
- DOI: https://doi.org/10.1016/j.jmb.2004.07.009
- Primary Citation of Related Structures:
1ULW, 1XQD - PubMed Abstract:
Nitric oxide reductase cytochrome P450nor catalyzes an unusual reaction, direct electron transfer from NAD(P)H to bound heme. Here, we succeeded in determining the crystal structure of P450nor in a complex with an NADH analogue, nicotinic acid adenine dinucleotide, which provides conclusive evidence for the mechanism of the unprecedented electron transfer. Comparison of the structure with those of dinucleotide-free forms revealed a global conformational change accompanied by intriguing local movements caused by the binding of the pyridine nucleotide. Arg64 and Arg174 fix the pyrophosphate moiety upon the dinucleotide binding. Stereo-selective hydride transfer from NADH to NO-bound heme was suggested from the structure, the nicotinic acid ring being fixed near the heme by the conserved Thr residue in the I-helix and the upward-shifted propionate side-chain of the heme. A proton channel near the NADH channel is formed upon the dinucleotide binding, which should direct continuous transfer of the hydride and proton. A salt-bridge network (Glu71-Arg64-Asp88) was shown to be crucial for a high catalytic turnover.
Organizational Affiliation:
Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, 113-8657, Japan.
