A Homolog of Old Yellow Enzyme in Tomato

Strassner, Jochen; Fürholz, Andreas; Macheroux, Peter; Amrhein, Nikolaus; Schaller, Andreas

doi:10.1074/jbc.274.49.35067

Cited by 103 publications

(44 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such phenolic compounds are known to bind in the deprotonated form (24), thereby indicating the ability of the protein to lower the pK a of the free phenol. From previous detailed studies (25), it seems reasonable to assume that it is the phenolate that binds to the enzyme and that the phenolate and the flavin act as the charge donor and acceptor, respectively (24).…”

Section: Expression and Purification Of Yq Jm-b Subtilis Yq Jm Wasmentioning

confidence: 99%

Characterization of YqjM, an Old Yellow Enzyme Homolog from Bacillus subtilis Involved in the Oxidative Stress Response

Fitzpatrick

Amrhein

Macheroux

2003

Journal of Biological Chemistry

Self Cite

165

145

View full text Add to dashboard Cite

In this paper, we demonstrate that a protein from Bacillus subtilis (Yq jM) shares many characteristic biochemical properties with the homologous yeast Old Yellow Enzyme (OYE); the enzyme binds FMN tightly but noncovalently, preferentially uses NADPH as a source of reducing equivalents, and forms charge transfer complexes with phenolic compounds such as p-hydroxybenzaldehyde. Like yeast OYE and other members of the family, Yq jM catalyzes the reduction of the double bond of an array of ␣,␤-unsaturated aldehydes and ketones including nitroester and nitroaromatic compounds. Although yeast OYE was the first member of this family to be discovered in 1933 and was the first flavoenzyme ever to be isolated, the physiological role of the family still remains obscure. The finding that ␣,␤-unsaturated compounds are substrates provoked speculation that the OYE family might be involved in reductive degradation of xenobiotics or lipid peroxidation products. Here, for the first time, we demonstrate on the protein level that whereas Yq jM shows a basal level of expression in B. subtilis, the addition of the toxic xenobiotic, trinitrotoluene, leads to a rapid induction of the protein in vivo denoting a role in detoxification. Moreover, we show that Yq jM is rapidly induced in response to oxidative stress as exerted by hydrogen peroxide, demonstrating a potential physiological role for this enigmatic class of proteins.

show abstract

Section: Expression and Purification Of Yq Jm-b Subtilis Yq Jm Wasmentioning

confidence: 99%

Characterization of YqjM, an Old Yellow Enzyme Homolog from Bacillus subtilis Involved in the Oxidative Stress Response

Fitzpatrick

Amrhein

Macheroux

2003

Journal of Biological Chemistry

Self Cite

165

145

View full text Add to dashboard Cite

show abstract

“…It should be noted that the Gln-114 in OYE1 is conserved in all members of the family. 12-Oxophytodienoate-10,11-reductase isozymes function in the jasmonic acid synthesis pathway of plants to reduce a double bond ␣,␤ to a ketone, converting 12-oxophytodienoic acid to 3-oxo-2-(pent2Јenyl)-cyclopentane-1-octanoic acid (20,28,30,34). Morphinone reductase from Pseudomonas putida M10 catalyzes the same sort of reaction, reducing morphinone to hydromorphinone (22).…”

mentioning

confidence: 99%

The Role of Glutamine 114 in Old Yellow Enzyme

Brown¹,

Hyun²,

Duvvuri³

et al. 2002

Journal of Biological Chemistry

View full text Add to dashboard Cite

Glutamine 114 of OYE1 is a well conserved residue in the active site of the Old Yellow Enzyme family. It forms hydrogen bonds to the O2 and N3 of the flavoprotein prosthetic group, FMN. Glutamine 114 was mutated to asparagine, introducing an R-group that is one methylene group shorter. The resultant enzyme was characterized to determine the effect of the mutation on the mechanistic behavior of the enzyme, and the crystal structure was solved to determine the effect of the mutation on the structure of the protein. The Q114N mutation results in little change in the protein structure, moving the amide group of residue 114 out of H-bonding distance, allowing repositioning of the FMN prosthetic group to form new interactions that replace the lost H-bonds. The mutation decreases the ability to bind ligands, as all dissociation constants for substituted phenols are larger than for the wild type enzyme. The rate constant for the reductive half-reaction with ␤-NADPH is slightly greater, whereas that for the oxidative half-reaction with 2-cyclohexenone is smaller than for the wild type enzyme. Oxidation with molecular oxygen is biphasic and involves formation and reaction with O 2 . , a phenomenon that is more pronounced with this mutation than with wild type enzyme. When superoxide dismutase is added to the reaction, we observe a single-phase reaction typical of the wild type enzyme. Turnover reactions using ␤-NADPH with 2-cyclohexenone and molecular oxygen were studied to further characterize the mutant enzyme.

show abstract

“…During the last few years, an increasing number of proteins have been isolated from bacterial, yeast, and plant sources, which share significant sequence identity with OYE (10)(11)(12)(13)(14)(15)(16)(17)(18). A number of these enzymes from microbial sources have been shown to catalyze the degradation of nitrate esters (19).…”

mentioning

confidence: 99%

Old yellow enzyme: Reduction of nitrate esters, glycerin trinitrate, and propylene 1,2-dinitrate

Meah

Brown

Chakraborty

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The reaction of the old yellow enzyme and reduced flavins with organic nitrate esters has been studied. Reduced flavins have been found to react readily with glycerin trinitrate (GTN ) (nitroglycerin) and propylene dinitrate, with rate constants at pH 7.0, 25°C of 145 M ؊1 s ؊1 and 5.8 M ؊1 s ؊1 , respectively. With GTN, the secondary nitrate was removed reductively 6 times faster than the primary nitrate, with liberation of nitrite. With propylene dinitrate, on the other hand, the primary nitrate residue was 3 times more reactive than the secondary residue. In the old yellow enzyme-catalyzed NADPH-dependent reduction of GTN and propylene dinitrate, ping-pong kinetics are displayed, as found for all other substrates of the enzyme. Rapid-reaction studies of mixing reduced enzyme with the nitrate esters show that a reduced enzyme-substrate complex is formed before oxidation of the reduced flavin. The rate constants for these reactions and the apparent Kd values of the enzyme-substrate complexes have been determined and reveal that the rate-limiting step in catalysis is reduction of the enzyme by NADPH. Analysis of the products reveal that with the enzymecatalyzed reactions, reduction of the primary nitrate in both GTN and propylene dinitrate is favored by comparison with the freeflavin reactions. This preferential positional reactivity can be rationalized by modeling of the substrates into the known crystal structure of the enzyme. In contrast to the facile reaction of free reduced flavins with GTN, reduced 5-deazaflavins have been found to react some 4 -5 orders of magnitude slower. This finding implies that the chemical mechanism of the reaction is one involving radical transfers.

show abstract

A Homolog of Old Yellow Enzyme in Tomato

Cited by 103 publications

References 29 publications

Characterization of YqjM, an Old Yellow Enzyme Homolog from Bacillus subtilis Involved in the Oxidative Stress Response

Characterization of YqjM, an Old Yellow Enzyme Homolog from Bacillus subtilis Involved in the Oxidative Stress Response

The Role of Glutamine 114 in Old Yellow Enzyme

Old yellow enzyme: Reduction of nitrate esters, glycerin trinitrate, and propylene 1,2-dinitrate

Contact Info

Product

Resources

About