Cytochrome from Pseudomonas stutzeri

Weeg-Aerssens, E., Wu, W., Ye, R. W., Tiedje, J. M., and Chang, C. K. (1991). Purification of cytochrome cdj nitrite reductase from Pseudomonas stutzeri JM 300 and reconstitution with native and synthetic heme di- ]. Biol. Chem. 266, 7496-7502. 

Zumft, W. G., Dohler, K., Ktirner, H., Lochelt, S., Viebrock, A., and Frunzke, K. (1988). Defects in cytochrome cd, dependent nitrite respiration of transposon Tn5-induced mutants from Pseudomonas stutzeri. Arch. Microbiol. 149, 492-498. 

Kadziola, A., and Larsen, S., 1997, Crystal structure of the dihaem cytochrome c4 from Pseudomonas stutzeri determined at 2.2A resolution. Structure 5 203n216. 

Cheesman, M., Ferguson, S. J., Moir, J. W. B., Richardson, D. J., Zumft, W. G., and Thomson, A. J., 1997, Two enzymes with a common function but different heme ligands. The optical and magnetic properties of the heme groups in the oxidised forms of nitrite reductase, cytochrome cdi, from Pseudomonas stutzeri and Thiosphaera pantotropha. Biochemistry 36 16267916276. 

The biological significance of fhese reachons is considered furfher in Chapters 18 and 24. The 132-kDa dimeric N2O reductase from Pseudomonas stutzeri contains four copper atoms per subunit. One of ifs copper cenfers resembles the Cu centers of cytochrome c oxidase. A second copper center consists of four copper ions, held by seven hisfidine side chains in a roughly tetrahedral array around one sulfide (S ) ion. Rasmussen et at. speculate that this copper-sulfide cluster may be an acceptor of fhe oxygen atoms of N2O in the formation of There is also a cyto-... 

Raffalt, A.C., Schmidt, L., Christensen, H.E.M., Chi, Q., and Ulstrup, J. (2009) Electron transfer patterns of the di-heme protein cytochrome c(4) from Pseudomonas stutzeri. Journal of Inorganic Biochemistry, 103, 717-722. 

Glockner, A. B., Jiingst, A., and Zumft, W. G. (1993). Copper-containing nitrite reductase from Pseudomonas aureofaciens is functional in a mutationally cytochrome cd,-free background (NirS ) of Pseudomonas stutzeri. Arch. Microbiol. 160, 18-26. 

This is a remarkable reaction because the transition metal chemistry of N2O is sparse, especially with copper. Most N2O reductases are soluble, periplasmic homodimers however, there are examples of membrane-associated enzymes. " The best characterized N2O reductases are from Paracoccus denitrificans, Pseudomonas nautica, and Pseudomonas stutzeri, and most of the information presented here is derived from experiments on these enzymes. Where comparable data are available, N2O reductases from various organisms appear to be fairly similar, with the exception of the enzyme from Wolinella succinogenes, as noted above. The crystal stractmes of N2O reductase from P. nautica and more recently from P. denitrificans show two distinct copper clusters per subunit a bis-thiolate bridged dinuclear electron-transfer site (Cua), which is analogous to the Cua site in cytochrome c oxidase see Cyanide Complexes of the Transition Metals), and a novel four-copper cluster ligated by seven histidines, the catalytic copper site (Cuz), where N2O is thought to bind and be reduced. Cuz was proposed to be a copper-histidine cluster on the basis of the presence of nine strictly conserved histidine residues, and this was supported by a H NMR study that identified two non-CuA associated resonances that were assigned as copper-histidine N-H protons. ... 

In addition to the ubiquinol oxidase mentioned above, cytochrome c oxidase is known, which contains heme O, as already described. Cytochrome aco (or cao3) has one molecule each of hemes A, B and O in the molecule, and shows cytochrome c oxidase activity (Qureshi et al., 1990). cytochromes co purified from Pseudomonas aeruginosa (Matsushita et al., 1982), Methylophilus methylotrophus (Fraud and Anthony, 1984) and Pseudomonas stutzeri (Heiss et al., 1989) also act as cytochrome c oxidase. 

Heiss B, Frunzke K, Zumft WG (1989) Formation of the N-N bond from nitric oxide by a membrane-bound cytochrome be complex of nitrate-respiring (denitrifying) Pseudomonas stutzeri. J Bacterid 171 3288-3297... 

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