Oxygenases dioxygenases

Key words nonheme iron complexes, functional models for oxygenases, dioxygenase-like and monooxygenase-like oxygenations, activation of molecular oxygen, radical and nonradical oxygenations, tridentate and tetradentate ligands... 

Oxygenases - add one (monooxygenases) or both (dioxygenases) atoms of molecular oxygen to molecules, eg... 

Sequences of proteins containing Rieske-type clusters have been deduced from the complete operons of several dioxygenases these dioxygenases require electrons from NAD(P)H to convert aromatic compounds to cis-arene diols. The water-soluble dioxygenase systems consist of a reductase and a terminal dioxygenase many dioxygenases also contain a [2Fe-2S] ferredoxin (20). The terminal oxygenases contain a Rieske-type cluster and the ferredoxins may contain either a Rieske-type or a 4-cysteine coordinated [2Fe-2S] cluster. 

The dioxygenase systems consist of a reductase and a terminal oxygenase many dioxygenases also contain a [2Fe-2S] ferredoxin. The reductase reacts with NAD(P)H it can be any of the following (20) ... 

Carotene cleavage enzymes — Two pathways have been described for P-carotene conversion to vitamin A (central and eccentric cleavage pathways) and reviewed recently. The major pathway is the central cleavage catalyzed by a cytosolic enzyme, p-carotene 15,15-oxygenase (BCO EC 1.13.1.21 or EC 1.14.99.36), which cleaves p-carotene at its central double bond (15,15 ) to form retinal. Two enzymatic mechanisms have been proposed (1) a dioxygenase reaction (EC 1.13.11.21) that requires O2 and yields a dioxetane as an intermediate and (2) a monooxygenase reaction (EC 1.14.99.36) that requires two oxygen atoms from two different sources (O2 and H2O) and yields an epoxide as an intermediate. ... 

It is clear from the preceding comments that there is no absolute distinction between the oxygenase activities mediated by dioxygenases. This is even less clear for heteroarenes than it is for carbocyclic compounds. An illustrative example is provided by Pseudomonas putida strain 86 in which 8-hydroxy-quinol-2-one is produced from quinol-2-one (Rosche et al. 1997). 

Hurtubise Y, D Barriault, M Sylvestre (1998) Involvement of the terminal oxygenase P subunit in the biphenyl dioxygenase reactivity pattern towards chlorobiphenyls. J Bacterial 180 5828-5835. 

Mampel J, J Ruff, F Junker, AM Cook (1999) The oxygenase component of the 2-aminobenzenesulfonate dioxygenase system from Alcaligenes sp. strain 0-1. Microbiology (UK) 145 3255-3264. 

Nakatsu CH, NA Straus, RC Wyndham (1995) The nucleotide sequence of the Tn 5271 3-chlorobenzoate 3,4-dioxygenase genes (cbaAB) unites the class lA oxygenases in a single linkage Microbiology (UK) 141 485-595. 

Neidle EL, C Hartnett, LN Ornmston, A Bairoch, M Rekin, S Harayama (1991) Nucleotide sequences of the Acinetobacter calcoaceticus benABC genes for benzoate 1,2-dioxygenase reveal evolutionary relationship among multicomponent oxygenases. J Bacteriol 173 5385-5395. 

Yamaguchi M, H Fujisawa (1982) Subunit structure of oxygenase components in benzoate 1,2-dioxygenase system from Pseudomonas arvilla C-1. J Biol Chem 257 12497-12502. 

Wolfe MD, JV Parales, DT Gibson, JD Lipscomb (2001) Single turnover chemistry and regulation of Oj activation by the oxygenase component of naphthalene 1,2-dioxygenase. J Biol Chem 276 1945-1953. 

Braaz R, W Armbruster, D Jendrossek (2005) Heme-dependent rubber oxygenase Roxa of Xanthomonas sp. cleaves the carbon backbone of poly(cw-l,4-isoprene) by a dioxygenase mechanism. Appl Environ Microbiol 71 2473-2478. 

Ensley BD, DT Gibson (1983) Naphthalene dioxygenase purification and properties of a terminal oxygenase component. J Bacteriol 155 505-511. 

Haddock JD, DT Gibson (1995) Purification and characterization of the oxygenase component of biphenyl 2,3-dioxygenase from Pseudomonas sp. strain LB400. J Bacteriol 177 5834-5839. 

Schlafli HR, MA Weiss, T Leisinger, AM Cook (1994) Terephthalate 1,2-dioxygenase system from Comamonas testosteroni T-2 purification and some properties of the oxygenase component. J Bacteriol 176 6644-6652. 

Chebrou H, Y Hurtubise, D Barriault, M Sylvestre (1999) Heterologous expression and cbaracterization of tbe pnrified oxygenase component of Rhodococcus globerulus P6 bipbenyl dioxygenase and of cbimeras derived from it. J Bacterial 181 4805-4811. 

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