Enzymes iron and

Three enzymes in Azotobacter vinelandii (Riittimann-Johnson et al. 2003) and Rho-dopseudomonas palustris (Oda et al. 2005) are capable of reducing dinitrogen the nif-encoded enzyme containing molybdenum and iron, the vn/that encodes a vanadium and iron enzyme, and the anf that is an iron-only enzyme. 

If our postulates are correct the most interesting feature of P-450 is the manner in which the protein has adjusted the coordination geometry of the iron and then provided near-neighbour reactive groups to take advantage of the activation generated by the curious coordination. Vallee and Williams (68) have observed this situation in zinc, copper and iron enzymes and referred to it as an entatic state of the protein. It is also apparent that some such adjustment of the coordination of cobalt occurs in the vitamin B12 dependent enzymes. As a final example we have looked at the absorption spectra of chlorophyll for its spectrum is in many respects very like that of a metal-porphyrin. This last note is intended to stress the features of chlorophyll chemistry which parallel those of P-450. 

Solomon El, Wong SD, Liu LV, Decker A, Chow MS. Peroxo and oxo intermediates in mononuclear nonheme iron enzymes and related active sites. Curr Opin Chem Biol. 2009 13 99-113. 

Although an X-ray crystal structure of MnRR has not been solved to date, a structure with Mn substituted into the iron ribonucleotide reductase has been reported (Fig. 6) (124). In this case, the two man-ganese(III) ions were bridged by two carboxylates from protein residues, but without the oxo bridge postulated for the active Fe1 form of the FeRR enzyme. This inactive enzyme with manganese was proposed as a model for the inactive Fe form of the iron enzyme and is... 

The molecular middle ground between nonheme di-iron enzymes and their small molecule synthetic analogues has been explored by de novo protein design. A protein can be designed to fold into a predetermined tertiary structure without patterning the sequence after any natural... 

Simurdiak M, Lee J, Zhao HM. 2006. A new class of arylamine oxygenases evidence that p-aminobenzoate N-oxygenase (AurF) is a di-iron enzyme and further mechanistic studies. ChemBioCheml 69- 12. 

Another plant phosphatase, from kidney bean, is also a dimer of approximately 130 kDa and further resembles the sweet potato enzyme in amino add composition and visible absorption spectrum Surprisingly, however, it is a zinc-iron enzyme and in some ways resembles the reconstituted zinc-iron derivative of uteroferrin Whether the zinc and iron atoms are neighbors is not yet known, but the possibility is appeahng. 

D. desulfuricans is able to grow on nitrate, inducing two enzymes that responsible for the steps of conversion of nitrate to nitrite (nitrate reductase-NAP), which is an iron-sulfur Mo-containing enzyme, and that for conversion of nitrite to ammonia (nitrite reduc-tase-NIR), which is a heme-containing enzyme. Nitrate reductase from D. desulfuricans is the only characterized enzyme isolated from a sulfate reducer that has this function. The enzyme is a monomer of 74 kDa and contains two MGD bound to a molybdenum and one [4Fe-4S] center (228, 229) in a single polypeptide chain of 753 amino acids. FXAFS data on the native nitrate reductase show that besides the two pterins coordinated to the molybdenum, there is a cysteine and a nonsulfur ligand, probably a Mo-OH (G. N. George, personal communication). 

Part 1 of the nitrogenase protein contains another interconnected group of Fe-S atoms, this one with eight iron atoms and seven sulfur atoms. This [8Fe-7S] group collects electrons and transmits them to the binding center. Part 2 of nitrogenase contains a third Fe-S group, this one made up of four iron atoms and four sulfur atoms. This part of the enzyme also binds two molecules of ATP. 

Nickel exists in the tunicate Trididemnum solidum as the nickel complex of a modified chlorin (Bible et al. 1988) and is a component of a number of enzymes. Urease is the classic example of a nickel-containing enzyme, and several enzymes contain both nickel and iron. Details of enzymes that contain nickel have been provided in a review (Mulrooney and Hausinger 2003), and only brief summaries are provided ... 

Selden, C., Seymour, C.A. and Peters, T.J. (1980). Activities of some free radical scavenging enzymes and glutathione concentrations in human and rat liver and their relationship to the pathogenesis of tissue damage in iron overload. Clin. Sci. 58, 211-219. 

Non-heme Di-Iron Enzymes Methane Monooxygenase and Ribonucleotide Reductase... 

Oxygen activation is a central theme in biochemistry and is performed by a wide range of different iron and copper enzymes. In addition to our studies of the dinuclear non-heme iron enzymes MMO and RNR, we also studied oxygen activation in the mononuclear non-heme iron enzyme isopenicillin N synthase (IPNS). This enzyme uses O2 to transform its substrate ACV to the penicillin precursor isopenicillin N [53], a key step in the synthesis of the important P-lactam antibiotics penicillins and cephalosporins [54, 55],... 

The active-site model (and the ONIOM model system) includes Fe, one aspartate and two histidine ligands, a water ligand and selected parts of the substrate (see Figure 2-6). The 2-histidine-1-carboxylate ligand theme is shared by several other non-heme iron enzymes [59], For the protein system, we used two different... 

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