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Ferrara S, Braggiotti B, Mastrangelo E, Di Gennaro P, Bertoni G, Milani M. Structural snapshots of the aldol condensation reaction of the enzyme trans-o-hydroxybenzylidenepyruvate hydratase-aldolase from Pseudomonas fluorescens N3. Biochem Biophys Res Commun 2025; 747:151281. [PMID: 39793398 DOI: 10.1016/j.bbrc.2024.151281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2024] [Accepted: 12/31/2024] [Indexed: 01/13/2025]
Abstract
Aldolases are crucial enzymes that catalyze the formation of carbon-carbon bonds in the context of the anabolic and catabolic pathways of various metabolites. The bacterium Pseudomonas fluorescens N3 can use naphthalene as its sole carbon and energy source by using, among other enzymes, the trans-o-hydroxybenzylidenepyruvate (tHBP) hydratase-aldolase (HA), encoded by the nahE gene. In this study, we present the crystallographic structures of tHBP-HA in three different functional states: the apo enzyme with a phosphate ion in the active site, and the Schiff base adduct bound either to pyruvate or to the substitute with '(R)-4-hydroxy-4-(2-hydroxyphenyl)-2-oxobutanoate'(intermediate state). Our structures elucidate some of the phases of the aldol condensation reaction, proposing the role of a conserved water molecule (W2) in the deprotonation of the catalytic lysine. Moreover, our crystallographic data suggest potential pathways for substrate and product diffusion to and from the protein's active site. These insights advance our understanding of the molecular mechanisms of the aldolase function and can also be used for the design and optimization of new enzymes engineered for the chemical synthesis of different C-C adducts.
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Affiliation(s)
- Silvia Ferrara
- Biophysics Institute, CNR-IBF, Via Corti 12, I-20133, Milano, Italy; Department of Bioscience, University of Milan, Via Celoria 26, I-20133, Milano, Italy
| | | | - Eloise Mastrangelo
- Biophysics Institute, CNR-IBF, Via Corti 12, I-20133, Milano, Italy; Department of Bioscience, University of Milan, Via Celoria 26, I-20133, Milano, Italy
| | - Patrizia Di Gennaro
- Department of Department of Biotechnology and Biosciences, University of Milano-Bicocca Piazza Dell'Ateneo Nuovo, I-20126, Milano, Italy
| | - Giovanni Bertoni
- Department of Bioscience, University of Milan, Via Celoria 26, I-20133, Milano, Italy
| | - Mario Milani
- Biophysics Institute, CNR-IBF, Via Corti 12, I-20133, Milano, Italy; Department of Bioscience, University of Milan, Via Celoria 26, I-20133, Milano, Italy.
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2
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Fansher DJ, Palmer DRJ. A Type 1 Aldolase, NahE, Catalyzes a Stereoselective Nitro-Michael Reaction: Synthesis of β-Aryl-γ-nitrobutyric Acids. Angew Chem Int Ed Engl 2023; 62:e202214539. [PMID: 36484780 DOI: 10.1002/anie.202214539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/27/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022]
Abstract
Michael addition reactions are highly useful in organic synthesis and are commonly accomplished using organocatalysts. However, the corresponding biocatalytic Michael additions are rare, typically lack synthetically useful substrate scope, and suffer from low stereoselectivity. Herein we report a biocatalytic nitro-Michael addition, catalyzed by NahE, that proceeds with low catalyst loading at room temperature in moderate to excellent enantioselectivity and high yields. A series of β-nitrostyrenes reacted with pyruvate in the presence of NahE to give, after oxidative decarboxylation, β-aryl-γ-nitrobutyric acids in up to 99 % yield without need for chromatography, providing a simple preparative-scale route to chiral GABA analogues. This reaction represents the first example of an aldolase displaying promiscuous Michaelase activity and opens the use of nitroalkenes in place of aldehydes as substrates for aldolases.
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Affiliation(s)
- Douglas J Fansher
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5C9, Canada
| | - David R J Palmer
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5C9, Canada
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3
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Lancaster EB, Johnson WH, LeVieux JA, Hardtke HA, Zhang YJ, Whitman CP. A mutagenic analysis of NahE, a hydratase-aldolase in the naphthalene degradative pathway. Arch Biochem Biophys 2023; 733:109471. [PMID: 36522814 PMCID: PMC9762252 DOI: 10.1016/j.abb.2022.109471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 11/19/2022] [Accepted: 11/21/2022] [Indexed: 11/27/2022]
Abstract
NahE is a hydratase-aldolase that converts o-substituted trans-benzylidenepyruvates (H, OH, or CO2-) to benzaldehyde, salicylaldehyde, or 2-carboxybenzaldehyde, respectively, and pyruvate. The enzyme is in a bacterial degradative pathway for naphthalene, which is a toxic and persistent environmental contaminant. Sequence, crystallographic, and mutagenic analysis identified the enzyme as a member of the N-acetylneuraminate lyase (NAL) subgroup in the aldolase superfamily. As such, it has a conserved lysine (Lys183) and tyrosine (Tyr155), for Schiff base formation, as well as a GXXGE motif for binding of the pyruvoyl carboxylate group. A crystal structure of the selenomethionine derivative of NahE shows these active site elements along with nearby residues that might be involved in the mechanism and/or specificity. Mutations of five active site amino acids (Thr65, Trp128, Tyr155, Asn157, and Asn281) were constructed and kinetic parameters measured in order to assess the effect(s) on catalysis. The results show that the two Trp128 mutants (Phe and Tyr) have the least effect on catalysis, whereas amino acids with bulky side chains at Thr65 (Val) and Asn281 (Leu) have the greatest effect. Changing Tyr155 to Phe and Asn157 to Ala also hinders catalysis, and the effects fall in between these extremes. These observations are put into a structural context using a crystal structure of the Schiff base of the reaction intermediate. Trapping experiments with substrate, Na(CN)BH3, and wild type enzyme and selected mutants mostly paralleled the kinetic analysis, and identified two salicylaldehyde-modified lysines: the active site lysine (Lys183) and one outside the active site (Lys279). The latter could be responsible for the observed inhibition of NahE by salicylaldehyde. Together, the results provide new insights into the NahE-catalyzed reaction.
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Affiliation(s)
- Emily B Lancaster
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas, Austin, TX, 78712, USA
| | - William H Johnson
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas, Austin, TX, 78712, USA
| | - Jake A LeVieux
- Department of Molecular Biosciences, and University of Texas, Austin, TX, 78712, USA
| | - Haley A Hardtke
- Department of Molecular Biosciences, and University of Texas, Austin, TX, 78712, USA
| | - Yan Jessie Zhang
- Department of Molecular Biosciences, and University of Texas, Austin, TX, 78712, USA; Institute for Cellular and Molecular Biology, University of Texas, Austin, TX, 78712, USA
| | - Christian P Whitman
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas, Austin, TX, 78712, USA; Institute for Cellular and Molecular Biology, University of Texas, Austin, TX, 78712, USA.
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Fansher DJ, Granger R, Kaur S, Palmer DRJ. Repurposing an Aldolase for the Chemoenzymatic Synthesis of Substituted Quinolines. ACS Catal 2021. [DOI: 10.1021/acscatal.1c01398] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Douglas J. Fansher
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5C9
| | - Richard Granger
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5C9
| | - Satinderpal Kaur
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5C9
| | - David R. J. Palmer
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5C9
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Mydy LS, Hoppe RW, Hagemann TM, Schwabacher AW, Silvaggi NR. Mechanistic Studies of the Streptomyces bingchenggensis Aldolase-Dehydratase: Implications for Substrate and Reaction Specificity in the Acetoacetate Decarboxylase-like Superfamily. Biochemistry 2019; 58:4136-4147. [PMID: 31524380 DOI: 10.1021/acs.biochem.9b00652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The acetoacetate decarboxylase-like superfamily (ADCSF) is a little-explored group of enzymes that may contain new biocatalysts. The low level of sequence identity (∼20%) between many ADCSF enzymes and the confirmed acetoacetate decarboxylases led us to investigate the degree of diversity in the reaction and substrate specificity of ADCSF enzymes. We have previously reported on Sbi00515, which belongs to Family V of the ADCSF and functions as an aldolase-dehydratase. Here, we more thoroughly characterize the substrate specificity of Sbi00515 and find that aromatic, unsaturated aldehydes yield lower KM and higher kcat values compared to those of other small electrophilic substrates in the condensation reaction. The roles of several active site residues were explored by site-directed mutagenesis and steady state kinetics. The lysine-glutamate catalytic dyad, conserved throughout the ADCSF, is required for catalysis. Tyrosine 252, which is unique to Sbi00515, is hypothesized to orient the incoming aldehyde in the condensation reaction. Transient state kinetics and an intermediate-bound crystal structure aid in completing a proposed mechanism for Sbi00515.
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Affiliation(s)
- Lisa S Mydy
- Department of Chemistry and Biochemistry , University of Wisconsin-Milwaukee , 3210 North Cramer Street , Milwaukee , Wisconsin 53211 , United States
| | - Robert W Hoppe
- Department of Chemistry and Biochemistry , University of Wisconsin-Milwaukee , 3210 North Cramer Street , Milwaukee , Wisconsin 53211 , United States
| | - Trevor M Hagemann
- Department of Chemistry and Biochemistry , University of Wisconsin-Milwaukee , 3210 North Cramer Street , Milwaukee , Wisconsin 53211 , United States
| | - Alan W Schwabacher
- Department of Chemistry and Biochemistry , University of Wisconsin-Milwaukee , 3210 North Cramer Street , Milwaukee , Wisconsin 53211 , United States
| | - Nicholas R Silvaggi
- Department of Chemistry and Biochemistry , University of Wisconsin-Milwaukee , 3210 North Cramer Street , Milwaukee , Wisconsin 53211 , United States
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Suzuki T, Takizawa N. Purification and enzymatic characterization of trans-o-hydroxybenzylidenepyruvate hydratase-aldolase from Rhodococcus opacus and enzymatic formation of α, β-unsaturated ketones. Biosci Biotechnol Biochem 2019; 83:1884-1888. [DOI: 10.1080/09168451.2019.1625262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
ABSTRACT
Trans-o-hydroxybenzylidenepyruvate (tHBPA) hydratase-aldolase (RnoE) catalyzes the conversion of tHBPA to 2-hydroxybenzaldehyde and pyruvate. We purified RnoE from Rhodococcus opacus and characterized its enzymatic properties. It exhibited maximum enzyme activity at 60°C and catalyzed the reverse reaction, converting various aromatic benzaldehydes and pyruvate to benzylidenepyruvate, indicating that this enzyme can be adapted for the enzymatic synthesis of α, β-unsaturated ketones.
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Affiliation(s)
- Toshihiro Suzuki
- Department of Fermentation Sciences, Faculty of Applied Biosciences, Tokyo University of Agriculture, Tokyo, Japan
| | - Noboru Takizawa
- Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Okayama University of Science, Okayama, Japan
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Spaltenstein P, Cummins EJ, Yokuda KM, Kowalczyk T, Clark TB, O'Neil GW. Chemoselective Carbonyl Allylations with Alkoxyallylsiletanes. J Org Chem 2019; 84:4421-4428. [PMID: 30811929 DOI: 10.1021/acs.joc.8b03028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Alkoxyallylsiletanes are capable of highly chemo- and diastereoselective carbonyl allylsilylations. Reactive substrates include salicylaldehydes and glyoxylic acids. Chemoselectivity in these reactions is thought to arise from a mechanism involving first exchange of the alkyoxy group on silicon with a substrate hydroxyl followed by activation of a nearby carbonyl by the Lewis acidic siletane and intramolecular allylation. In this way, substrates containing multiple reactive carbonyl groups (e.g., dialdehyde or triketone) can be selectively monoallylated, even overcoming inherent electrophilicity bias.
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Affiliation(s)
- Paul Spaltenstein
- Department of Chemistry , Western Washington University , Bellingham , Washington 98225 , United States
| | - Elizabeth J Cummins
- Department of Chemistry , Western Washington University , Bellingham , Washington 98225 , United States
| | - Kelly-Marie Yokuda
- Department of Chemistry , Western Washington University , Bellingham , Washington 98225 , United States
| | - Tim Kowalczyk
- Department of Chemistry , Western Washington University , Bellingham , Washington 98225 , United States
| | - Timothy B Clark
- Department of Chemistry , University of San Diego , San Diego , California 92110 , United States
| | - Gregory W O'Neil
- Department of Chemistry , Western Washington University , Bellingham , Washington 98225 , United States
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8
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Mydy LS, Hoppe RW, Ochsenwald JM, Berndt RT, Severin GB, Schwabacher AW, Silvaggi NR. Sbi00515, a Protein of Unknown Function from Streptomyces bingchenggensis, Highlights the Functional Versatility of the Acetoacetate Decarboxylase Scaffold. Biochemistry 2015; 54:3978-88. [PMID: 26039798 DOI: 10.1021/acs.biochem.5b00483] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The acetoacetate decarboxylase-like superfamily (ADCSF) is a group of ~4000 enzymes that, until recently, was thought to be homogeneous in terms of the reaction catalyzed. Bioinformatic analysis shows that the ADCSF consists of up to seven families that differ primarily in their active site architectures. The soil-dwelling bacterium Streptomyces bingchenggensis BCW-1 produces an ADCSF enzyme of unknown function that shares a low level of sequence identity (~20%) with known acetoacetate decarboxylases (ADCs). This enzyme, Sbi00515, belongs to the MppR-like family of the ADCSF because of its similarity to the mannopeptimycin biosynthetic protein MppR from Streptomyces hygroscopicus. Herein, we present steady state kinetic data that show Sbi00515 does not catalyze the decarboxylation of any α- or β-keto acid tested. Rather, we show that Sbi00515 catalyzes the condensation of pyruvate with a number of aldehydes, followed by dehydration of the presumed aldol intermediate. Thus, Sbi00515 is a pyruvate aldolase-dehydratase and not an acetoacetate decarboxylase. We have also determined the X-ray crystal structures of Sbi00515 in complexes with formate and pyruvate. The structures show that the overall fold of Sbi00515 is nearly identical to those of both ADC and MppR. The pyruvate complex is trapped as the Schiff base, providing evidence that the Schiff base chemistry that drives the acetoacetate decarboxylases has been co-opted to perform a new function, and that this core chemistry may be conserved across the superfamily. The structures also suggest possible catalytic roles for several active site residues.
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Affiliation(s)
- Lisa S Mydy
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 North Cramer Street, Milwaukee, Wisconsin 53211, United States
| | - Robert W Hoppe
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 North Cramer Street, Milwaukee, Wisconsin 53211, United States
| | - Jenna M Ochsenwald
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 North Cramer Street, Milwaukee, Wisconsin 53211, United States
| | - Robert T Berndt
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 North Cramer Street, Milwaukee, Wisconsin 53211, United States
| | - Geoffrey B Severin
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 North Cramer Street, Milwaukee, Wisconsin 53211, United States
| | - Alan W Schwabacher
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 North Cramer Street, Milwaukee, Wisconsin 53211, United States
| | - Nicholas R Silvaggi
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 North Cramer Street, Milwaukee, Wisconsin 53211, United States
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