Dioxygenases 2-ketoglutarate

Nickel K, MJ-F Suter, H-PE Kohler (1997) Involvement of two 3-ketoglutarate-dependent dioxygenases in enantioselective degradation of R)- and (S)-mecoprop by Sphingomonas herbicidovorans MH. Appl Environ Microbiol 63 6674-6679. 

Eichhorn E, JR van der Ploeg, MA Kertesz, T Leisinger (1997) Characterization of an a-ketoglutarate-depen-dent taurine dioxygenase from Escherichia coli. J Biol Chem 272 23031-23036. 

Fukumori F, RP Hausinger (1993a) Alcaligenes eutrophus JMP 134 2,4-chlorophenoxyacetate monooxygenase is an a-ketoglutarate-dependent dioxygenase. J Bacterial 175 2083-2086. 

Matheson VG, LJ, Forney, Y Suwa, CH Nakatsu, AJ Sextone, AJ, WE Holben (1996) Evidence for acquisition in nature of a chromosomal 2,4-dichlorophenoxyacetic acid/a-ketoglutarate dioxygenase gene by different Burckholderia spp. Appl Environ Microbiol 62 2457-2463. 

Stubbe J (1985) Identification of two a-ketoglutarate-dependent dioxygenases in extracts of Rhodotolula glutinis catalyzing deoxyuridine hydroxylation J Biol Chem 260 9972-9975. 

Suwa Y, WE Olben, LJ Eorney (1996) Characterization of chromosomally encoded 2,4-dichlorophenoxyace-tic acid-a-ketoglutarate dioxygenase from Burkholderia sp. strain RASC. Appl Environ Microbiol 62 2464-2469. 

Sassanella TM, F Fukumori, M Bagdasarian, RP Hausinger (1997) Use of 4-nitrophenoxyacetic acid for detection and quantification of 2,4-dichlorophenoxyacetic acid 2,4-D/a-ketoglutarate dioxygenase activity in 2,4- D-degrading microorganisms. Appl Environ Microbiol 63 1189-1191. 

Figure 13.21 Mononuclear non-haem iron enzymes from each of the five families in structures which are poised for attack by 02. (a) The extradiol-cleaving catechol dioxygenase, 2,3-dihydroxy-biphenyl 1,2-dioxygenase (b) the Rieske dioxygenase, naphthalene 1,2-dioxygenase (c) isopenicillin N-synthase (d) the ot-ketoglutarate dependent enzyme clavaminate synthase and (e) the pterin-dependent phenylalanine hydroxylase. (From Koehntop et al., 2005. With kind permission of Springer Science and Business Media.)...

This enzyme [EC 1.14.11.1], also known as y-butyrobe-taine, 2-ketoglutarate dioxygenase, catalyzes the reaction of 4-trimethylammoniobutanoate with S-keto-glutarate (or, 2-oxoglutarate) and dioxygen to yield 3-hydroxy-4-trimethylammoniobutanoate, succinate, and carbon dioxide. Both iron ions and ascorbate are needed as cofactors. 

The mechanism of a-ketoglutarate participation in the dioxygenase reaction has been proposed by Lindstedt and his co-workers6S,220) as shown in Eq. (27) with y-butyrobetaine hydroxylase. 

A very different but equally direct mechanism is used to repair 1-methyladenine and 3-methylcytosine. The amino groups of A and C residues are sometimes methylated when the DNA is single-stranded, and the methylation directly affects proper base pairing. In E. coli, oxidative demethylation of these alkylated nucleotides is mediated by the AllcB protein, a member of the a-ketoglutarate-Fe2+-dependent dioxygenase superfamily (Fig. 25-27). (See Box 4-3 for a description of another member of this enzyme family.)... 

FIGURE 25-27 Direct repair of alkylated bases by AlkB. The AlkB protein is an a-ketoglutarate-Fe2+-dependent dioxygenase. It catalyzes the oxidative demethylation of 1-methyladenine and 3-methyl-cytosine residues. 

MT Abbott, S Udenfriend. cx-Ketoglutarate-coupled dioxygenases. In O Hayashi, ed. Molecular Mechanisms of Oxygen Activation. New York Academic Press, 1974, pp 167-214. 

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