Characterization of the Ferrous Ion Binding Sites of Apple 1-Aminocyclopropane-1-carboxylate Oxidase by Site-Directed Mutagenesis

Shaw, Jei‐Fu; Chou, Y. S.; Chang, Rey-Chang; Yang, Shang Fa

doi:10.1006/bbrc.1996.1237

Cited by 38 publications

(25 citation statements)

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“…A GenBank Blastp search revealed that the resulting nucleotide sequences of MaACO1 and MaACT1 shared high identity with those of other species. The predicted mulberry ACC oxidase gene (MaACO1) amino acid sequence has a motif similar to the putative Fe 2+ binding sites (His177, Asp179, and His234) of the apple ACO gene (Shaw et al, 1996), and the 3 0 UTR sequence has a TTTGTA far-upstream element that exists in the white clover gene, TRACO3 but not in TRACO1 or in TRACO2 (Hunter et al, 1999). These results support the function of MaACO1 as an ACC oxidase.…”

Section: Isolation Of Acc Oxidase Gene and Actin Gene From Mulberrysupporting

confidence: 57%

Isolation of an 1-aminocyclopropane-1-carboxylate oxidase gene from mulberry (Morus alba L.) and analysis of the function of this gene in plant development and stresses response

Pan

Chengfu

2008

Journal of Plant Physiology

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Section: Isolation Of Acc Oxidase Gene and Actin Gene From Mulberrysupporting

confidence: 57%

Isolation of an 1-aminocyclopropane-1-carboxylate oxidase gene from mulberry (Morus alba L.) and analysis of the function of this gene in plant development and stresses response

Pan

Chengfu

2008

Journal of Plant Physiology

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“…Similar results are reported for metabolite-transforming enzymes such as phytanoyl-CoA hydroxylase (PAHX) [41,42], CAS [43], 2,4-dichlorophenoxyacetic acid hydroxylase (TfdA) [44], and a bacterial ethyleneforming enzyme [45]. For the sequence-related aKG-independent enzymes 1-aminocyclopropane-1-carboxylate (ACC) oxidase and isopenicillin N synthase (IPNS), the comparable His residue in each protein was extensively mutagenized and all of the variants are inactive except for 1% of the wild-type activity reported for H177Q ACC oxidase [46][47][48][49][50][51][52]. In marked contrast, substitution of the His ligand by Ala in (S)-2-hydroxypropylphosphonic acid epoxidase (HppE) led to an enzyme variant that retains 20% of the activity of the wild-type enzyme [53].…”

Section: Relationship Of the Taud Results To Mutagenesis Studies Of Omentioning

confidence: 98%

Metal ligand substitution and evidence for quinone formation in taurine/α-ketoglutarate dioxygenase

Grzyska¹,

Müller²,

Campbell³

et al. 2007

Journal of Inorganic Biochemistry

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“…Although the sequence homology among these enzymes is not high, all their active sites contain a single ferrous ion bound in a tridendate ligand arrangement referred to as a ''2-His-1-carboxylate facial triad'' (4). A crystal structure of ACCO has been reported (6), revealing a solvent-exposed active site and confirming the ligation of the iron center (His-177, Asp-179, and His-234) inferred from mutagenesis studies (7), and the general jellyroll motif found in other nonheme iron enzymes (8,9).…”

mentioning

confidence: 82%

The nature of O ₂ activation by the ethylene-forming enzyme 1-aminocyclopropane-1-carboxylic acid oxidase

Mirica

Klinman

2008

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

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Ethylene is a plant hormone important in many aspects of plant growth and development such as germination, fruit ripening, and senescence. 1-Aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACCO), an O 2-activating ascorbate-dependent nonheme iron enzyme, catalyzes the last step in ethylene biosynthesis. The O 2 activation process by ACCO was investigated using steady-state kinetics, solvent isotope effects (SIEs), and competitive oxygen kinetic isotope effects ( 18 O KIEs) to provide insights into the nature of the activated oxygen species formed at the active-site iron center and its dependence on ascorbic acid. The observed large 18 2 His, 1-Asp proteins ͉ high-valent iron oxo species ͉ oxygen-18 kinetic isotope effects ͉ nonheme iron enzymes E thylene is a major plant hormone important in many aspects of plant growth and development such as germination, fruit ripening, and senescence (1). The ability to control ethylene formation in a time-dependent manner would have far-reaching economic, agricultural, and environmental implications. The last step in the biosynthesis of ethylene, the two electron oxidation of 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene, CO 2 , and HCN, is catalyzed by ACC oxidase (ACCO) (2-4). This reaction also requires the concomitant reduction of O 2 to water and the oxidation of ascorbate to dehydroascorbate (Fig. 1), whereas CO 2 (or bicarbonate) has been shown to act as an activator for ethylene formation (5).ACCO belongs to the family of O 2 -activating nonheme iron enzymes. Although the sequence homology among these enzymes is not high, all their active sites contain a single ferrous ion bound in a tridendate ligand arrangement referred to as a ''2-His-1-carboxylate facial triad'' (4). A crystal structure of ACCO has been reported (6), revealing a solvent-exposed active site and confirming the ligation of the iron center (His-177, Asp-179, and His-234) inferred from mutagenesis studies (7), and the general jellyroll motif found in other nonheme iron enzymes (8,9).What distinguishes ACCO from the other enzymes of this family is the two-electron donating cosubstrate needed for reducing O 2 to water: ascorbate in the case of ACCO (10-13) and ␣-ketoglutarate (␣KG) in almost all other known examples (4). The mechanism of ␣KG-dependent enzymes has been studied extensively, and it generally is accepted that O 2 activation at the iron center is linked to oxidative decarboxylation of the ␣KG, ultimately forming an Fe IV AO species as the reactive intermediate (14)(15)(16)(17). This high-valent Fe/O 2 species functions as a ''generic'' oxidant for a wide range of oxidation/oxygenation reactions.In contrast to the ␣KG-dependent enzymes, where ␣KG rather than substrate binds to the metal center, spectroscopic studies of ACCO have shown that ACC coordinates to the iron center via both its amino and carboxylate groups (10,18).† This finding implies a distinctly different mode for reductant interaction with ACCO than for most other nonheme iron enzymes. Magnetic circular dichroism ...

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Characterization of the Ferrous Ion Binding Sites of Apple 1-Aminocyclopropane-1-carboxylate Oxidase by Site-Directed Mutagenesis

Cited by 38 publications

References 0 publications

Isolation of an 1-aminocyclopropane-1-carboxylate oxidase gene from mulberry (Morus alba L.) and analysis of the function of this gene in plant development and stresses response

Isolation of an 1-aminocyclopropane-1-carboxylate oxidase gene from mulberry (Morus alba L.) and analysis of the function of this gene in plant development and stresses response

Metal ligand substitution and evidence for quinone formation in taurine/α-ketoglutarate dioxygenase

The nature of O ₂ activation by the ethylene-forming enzyme 1-aminocyclopropane-1-carboxylic acid oxidase

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Characterization of the Ferrous Ion Binding Sites of Apple 1-Aminocyclopropane-1-carboxylate Oxidase by Site-Directed Mutagenesis

Cited by 38 publications

References 0 publications

Isolation of an 1-aminocyclopropane-1-carboxylate oxidase gene from mulberry (Morus alba L.) and analysis of the function of this gene in plant development and stresses response

Isolation of an 1-aminocyclopropane-1-carboxylate oxidase gene from mulberry (Morus alba L.) and analysis of the function of this gene in plant development and stresses response

Metal ligand substitution and evidence for quinone formation in taurine/α-ketoglutarate dioxygenase

The nature of O 2 activation by the ethylene-forming enzyme 1-aminocyclopropane-1-carboxylic acid oxidase

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The nature of O ₂ activation by the ethylene-forming enzyme 1-aminocyclopropane-1-carboxylic acid oxidase