Alice S. Pereira
Associate Professor
Department of Chemistry, FCT/UNL, 2829-516 Caparica, Portugal (email)
Department of Chemistry, FCT/UNL, 2829-516 Caparica, Portugal (email)
Nitrous oxide (N(2)O) is a greenhouse gas, the third most significant contributor to global warming. As a key process for N(2)O elimination from the biosphere, N(2)O reductases catalyze the two-electron reduction of N(2)O to N(2). These 2 x 65 kDa copper enzymes are thought to contain a CuA electron entry site, similar to that of cytochrome c oxidase, and a CuZ catalytic center. The copper anomalous signal was used to solve the crystal structure of N(2)O reductase from Pseudomonas nautica by multiwavelength anomalous dispersion, to a resolution of 2.4 Angstrom. The structure reveals that the CuZ center belongs to a new type of metal cluster, in which four copper ions are liganded by seven histidine residues. N(2)O binds to this center via a single copper ion. The remaining copper ions might act as an electron reservoir, assuring a fast electron transfer and avoiding the formation of dead-end products.
Times Cited: 166 Brown, K Tegoni, M Prudencio, M Pereira, AS Besson, S Moura, JJ Moura, I Cambillau, C