A Novel A3 Group Aconitase Tolerates Oxidation and Nitric Oxide

Doi, Yuki; Takaya, Naoki

doi:10.1074/jbc.m114.614164

Cited by 8 publications

(4 citation statements)

References 40 publications

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“…This method was used to clarify the optimum pH for enzyme activity. Potential Acn activity in PaLhpI protein was measured spectrophotometrically by monitoring the change of absorption at 240 nm derived from unsaturated cis -aconitate49.…”

Section: Methodsmentioning

confidence: 99%

Functional characterization of aconitase X as a cis-3-hydroxy-L-proline dehydratase

Watanabe

Tajima

Fujii

et al. 2016

Sci Rep

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In the aconitase superfamily, which includes the archetypical aconitase, homoaconitase, and isopropylmalate isomerase, only aconitase X is not functionally annotated. The corresponding gene (LhpI) was often located within the bacterial gene cluster involved in L-hydroxyproline metabolism. Screening of a library of (hydroxy)proline analogues revealed that this protein catalyzes the dehydration of cis-3-hydroxy-L-proline to Δ1-pyrroline-2-carboxylate. Furthermore, electron paramagnetic resonance and site-directed mutagenic analyses suggests the presence of a mononuclear Fe(III) center, which may be coordinated with one glutamate and two cysteine residues. These properties were significantly different from those of other aconitase members, which catalyze the isomerization of α- to β-hydroxy acids, and have a [4Fe-4S] cluster-binding site composed of three cysteine residues. Bacteria with the LhpI gene could degrade cis-3-hydroxy-L-proline as the sole carbon source, and LhpI transcription was up-regulated not only by cis-3-hydroxy-L-proline, but also by several isomeric 3- and 4-hydroxyprolines.

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Section: Methodsmentioning

confidence: 99%

Functional characterization of aconitase X as a cis-3-hydroxy-L-proline dehydratase

Watanabe

Tajima

Fujii

et al. 2016

Sci Rep

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“…However, similar to the rest of the Alphaproteobacteria, G. diazotrophicus lacks a LuxS homolog required for AI-2 synthesis (Rezzonico & Duffy, 2008), so the up-accumulation of MetE in our proteomic analysis should not be related to QS activity. Another up-accumulated protein was Aconitate hydratase (AcnA), which is associated with the metabolism of tricarboxylic acids and may protect bacterial cells from reactive oxygen species (Doi & Takaya, 2015). Ketol-acid reductoisomerase (IlvC), which was also up-accumulated, plays an essential role in the pathway of amino acid biosynthesis (Li et al, 2017).…”

Section: Discussionmentioning

confidence: 99%

Arabidopsis thaliana exudates induce growth and proteomic changes in Gluconacetobacter diazotrophicus

Santos

Leandro

Maia

et al. 2020

PeerJ

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Background Plants interact with a variety of microorganisms during their life cycle, among which beneficial bacteria deserve special attention. Gluconacetobacter diazotrophicus is a beneficial bacterium able to fix nitrogen and promote plant growth. Despite its biotechnological potential, the mechanisms regulating the interaction between G. diazotrophicus and host plants remain unclear. Methods We analyzed the response of G. diazotrophicus to cocultivation with Arabidopsis thaliana seedlings. Bacterial growth in response to cocultivation and plant exudates was analyzed. Through comparative proteomic analysis, G. diazotrophicus proteins regulated during cocultivation were investigated. Finally, the role of some up-accumulated proteins in the response G. diazotrophicus to cocultivation was analyzed by reverse genetics, using insertion mutants. Results Our results revealed the induction of bacterial growth in response to cocultivation. Comparative proteomic analysis identified 450 bacterial proteins, with 39 up-accumulated, and 12 down-accumulated in response to cocultivation. Among the up-accumulated pathways, the metabolism of pentoses and protein synthesis were highlighted. Proteins potentially relevant to bacterial growth response such as ABC-F-Etta, ClpX, Zwf, MetE, AcnA, IlvC, and AccC were also increased. Reverse genetics analysis, using insertion mutants, revealed that the lack of ABC-F-Etta and AccC proteins severely affects G. diazotrophicus response to cocultivation. Our data demonstrated that specific mechanisms are activated in the bacterial response to plant exudates, indicating the essential role of “ribosomal activity” and “fatty acid biosynthesis” in such a process. This is the first study to demonstrate the participation of EttA and AccC proteins in plant-bacteria interactions, and open new perspectives for understanding the initial steps of such associations.

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“…Pyruvate dehydrogenase activity was measured in 100 µL reactions containing cellfree extract (20 µL) as described in [25]. Aconitase activity was measured as described in [9,26] with some modifications; the reactions (100 µL) contained 50 mM Tris-HCl (pH 8.0), 1 mM cis-aconitate, 1 mM MgCl 2 , 2 mM NADP + , 1 unit mL −1 isocitrate dehydrogenase (Fujifilm Wako Pure Chemical Corp., Osaka, Japan), and 20 µL of cell-free extracts. The absorbance at 340 nm was monitored using NADPH and changes were calculated using a molar extinction coefficient of 6.22 mM −1 cm −1 .…”

Section: Enzyme Activitymentioning

confidence: 99%

The Metabolic Regulation of Amino Acid Synthesis Counteracts Reactive Nitrogen Stress via Aspergillus nidulans Cross-Pathway Control

Amahisa,

Tsukagoshi,

Kadooka

et al. 2024

JoF

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Nitric oxide (NO) is a natural reactive nitrogen species (RNS) that alters proteins, DNA, and lipids and damages biological activities. Although microorganisms respond to and detoxify NO, the regulation of the cellular metabolic mechanisms that cause cells to tolerate RNS toxicity is not completely understood. We found that the proline and arginine auxotrophic proA5 and argB2 mutants of the fungus Aspergillus nidulans require more arginine and proline for normal growth under RNS stress that starves cells by accumulating fewer amino acids. Fungal transcriptomes indicated that RNS stress upregulates the expression of the biosynthetic genes required for global amino acids, including proline and arginine. A mutant of the gene disruptant, cpcA, which encodes the transcriptional regulation of the cross-pathway control of general amino acid synthesis, did not induce these genes, and cells accumulated fewer amino acids under RNS stress. These results indicated a novel function of CpcA in the cellular response to RNS stress, which is mediated through amino acid starvation and induces the transcription of genes for general amino acid synthesis. Since CpcA also controls organic acid biosynthesis, impaired intermediates of such biosynthesis might starve cells of amino acids. These findings revealed the importance of the mechanism regulating amino acid homeostasis for fungal responses to and survival under RNS stress.

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A Novel A3 Group Aconitase Tolerates Oxidation and Nitric Oxide

Cited by 8 publications

References 40 publications

Functional characterization of aconitase X as a cis-3-hydroxy-L-proline dehydratase

Functional characterization of aconitase X as a cis-3-hydroxy-L-proline dehydratase

Arabidopsis thaliana exudates induce growth and proteomic changes in Gluconacetobacter diazotrophicus

The Metabolic Regulation of Amino Acid Synthesis Counteracts Reactive Nitrogen Stress via Aspergillus nidulans Cross-Pathway Control

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