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Dali A, Gabler T, Sebastiani F, Furtmüller PG, Becucci M, Hofbauer S, Smulevich G. Entrance channels to coproheme in coproporphyrin ferrochelatase probed by exogenous imidazole binding. J Inorg Biochem 2024; 260:112681. [PMID: 39146673 DOI: 10.1016/j.jinorgbio.2024.112681] [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: 05/17/2024] [Revised: 07/25/2024] [Accepted: 07/27/2024] [Indexed: 08/17/2024]
Abstract
Iron insertion into porphyrins is an essential step in heme biosynthesis. In the coproporphyrin-dependent pathway, specific to monoderm bacteria, this reaction is catalyzed by the monomeric enzyme coproporphyrin ferrochelatase. In addition to the mechanistic details of the metalation of the porphyrin, the identification of the substrate access channel for ferrous iron to the active site is important to fully understand this enzymatic system. In fact, whether the iron reaches the active site from the distal or the proximal porphyrin side is still under debate. In this study we have thoroughly addressed this question in Listeria monocytogenes coproporphyrin ferrochelatase by X-ray crystallography, steady-state and pre-steady-state imidazole ligand binding studies, together with a detailed spectroscopic characterization using resonance Raman and UV-vis absorption spectroscopies in solution. Analysis of the X-ray structures of coproporphyrin ferrochelatase-coproporphyrin III crystals soaked with ferrous iron shows that iron is present on both sides of the porphyrin. The kinetic and spectroscopic study of imidazole binding to coproporphyrin ferrochelatase‑iron coproporphyrin III clearly indicates the presence of two possible binding sites in this monomeric enzyme that influence each other, which is confirmed by the observed cooperativity at steady-state and a biphasic behavior in the pre-steady-state experiments. The current results are discussed in the context of the entire heme biosynthetic pathway and pave the way for future studies focusing on protein-protein interactions.
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Affiliation(s)
- Andrea Dali
- Dipartimento di Chimica "Ugo Schiff" (DICUS), Università di Firenze, Via della Lastruccia 3-13, I-50019 Sesto Fiorentino (FI), Italy
| | - Thomas Gabler
- BOKU University, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, A-1190 Vienna, Austria
| | - Federico Sebastiani
- Dipartimento di Chimica "Ugo Schiff" (DICUS), Università di Firenze, Via della Lastruccia 3-13, I-50019 Sesto Fiorentino (FI), Italy
| | - Paul G Furtmüller
- BOKU University, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, A-1190 Vienna, Austria
| | - Maurizio Becucci
- Dipartimento di Chimica "Ugo Schiff" (DICUS), Università di Firenze, Via della Lastruccia 3-13, I-50019 Sesto Fiorentino (FI), Italy; The European Laboratory for Non-Linear Spectroscopy (LENS), Via Nello Carrara 1, I-50019 Sesto Fiorentino (FI), Italy.
| | - Stefan Hofbauer
- BOKU University, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, A-1190 Vienna, Austria.
| | - Giulietta Smulevich
- Dipartimento di Chimica "Ugo Schiff" (DICUS), Università di Firenze, Via della Lastruccia 3-13, I-50019 Sesto Fiorentino (FI), Italy; INSTM Research Unit of Firenze, Via della Lastruccia 3, I-50019 Sesto Fiorentino (FI), Italy.
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2
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Gabler T, Dali A, Bellei M, Sebastiani F, Becucci M, Battistuzzi G, Furtmüller PG, Smulevich G, Hofbauer S. Revisiting catalytic His and Glu residues in coproporphyrin ferrochelatase - unexpected activities of active site variants. FEBS J 2024; 291:2260-2272. [PMID: 38390750 DOI: 10.1111/febs.17101] [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: 12/13/2023] [Revised: 01/17/2024] [Accepted: 02/13/2024] [Indexed: 02/24/2024]
Abstract
The identification of the coproporphyrin-dependent heme biosynthetic pathway, which is used almost exclusively by monoderm bacteria in 2015 by Dailey et al. triggered studies aimed at investigating the enzymes involved in this pathway that were originally assigned to the protoporphyrin-dependent heme biosynthetic pathway. Here, we revisit the active site of coproporphyrin ferrochelatase by a biophysical and biochemical investigation using the physiological substrate coproporphyrin III, which in contrast to the previously used substrate protoporphyrin IX has four propionate substituents and no vinyl groups. In particular, we have compared the reactivity of wild-type coproporphyrin ferrochelatase from the firmicute Listeria monocytogenes with those of variants, namely, His182Ala (H182A) and Glu263Gln (E263Q), involving two key active site residues. Interestingly, both variants are active only toward the physiological substrate coproporphyrin III but inactive toward protoporphyrin IX. In addition, E263 exchange impairs the final oxidation step from ferrous coproheme to ferric coproheme. The characteristics of the active site in the context of the residues involved and the substrate binding properties are discussed here using structural and functional means, providing a further contribution to the deciphering of this enigmatic reaction mechanism.
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Affiliation(s)
- Thomas Gabler
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Andrea Dali
- Department of Chemistry "Ugo Schiff" (DICUS), University of Florence, Sesto Fiorentino, Italy
| | - Marzia Bellei
- Department of Life Sciences, University of Modena and Reggio Emilia, Italy
| | - Federico Sebastiani
- Department of Chemistry "Ugo Schiff" (DICUS), University of Florence, Sesto Fiorentino, Italy
| | - Maurizio Becucci
- Department of Chemistry "Ugo Schiff" (DICUS), University of Florence, Sesto Fiorentino, Italy
| | - Gianantonio Battistuzzi
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Paul Georg Furtmüller
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Giulietta Smulevich
- Department of Chemistry "Ugo Schiff" (DICUS), University of Florence, Sesto Fiorentino, Italy
- INSTM Research Unit of Firenze, Sesto Fiorentino, Italy
| | - Stefan Hofbauer
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, Vienna, Austria
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3
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Jackson LK, Dailey TA, Anderle B, Warren MJ, Bergonia HA, Dailey HA, Phillips JD. Exploiting Differences in Heme Biosynthesis between Bacterial Species to Screen for Novel Antimicrobials. Biomolecules 2023; 13:1485. [PMID: 37892169 PMCID: PMC10604556 DOI: 10.3390/biom13101485] [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: 09/14/2023] [Revised: 10/02/2023] [Accepted: 10/03/2023] [Indexed: 10/29/2023] Open
Abstract
The final three steps of heme biogenesis exhibit notable differences between di- and mono-derm bacteria. The former employs the protoporphyrin-dependent (PPD) pathway, while the latter utilizes the more recently uncovered coproporphyrin-dependent (CPD) pathway. In order to devise a rapid screen for potential inhibitors that differentiate the two pathways, the genes associated with the protoporphyrin pathway in an Escherichia coli YFP strain were replaced with those for the CPD pathway from Staphylococcus aureus (SA) through a sliding modular gene replacement recombineering strategy to generate the E. coli strain Sa-CPD-YFP. Potential inhibitors that differentially target the pathways were identified by screening compound libraries against the YFP-producing Sa-CPD-YFP strain in comparison to a CFP-producing E. coli strain. Using a mixed strain assay, inhibitors targeting either the CPD or PPD heme pathways were identified through a decrease in one fluorescent signal but not the other. An initial screen identified both azole and prodigiosin-derived compounds that were shown to specifically target the CPD pathway and which led to the accumulation of coproheme, indicating that the main target of inhibition would appear to be the coproheme decarboxylase (ChdC) enzyme. In silico modeling highlighted that these inhibitors are able to bind within the active site of ChdC.
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Affiliation(s)
- Laurie K. Jackson
- Department of Internal Medicine, Division of Hematology, University of Utah, Salt Lake City, UT 84112, USA; (L.K.J.); (H.A.B.)
| | - Tammy A. Dailey
- Department of Microbiology, Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA (H.A.D.)
| | - Brenden Anderle
- WhiteTree Medical, 10437 S Jordan Gateway, South Jordan, UT 84095, USA;
| | - Martin J. Warren
- Quadram Institute Bioscience, Norwich Research Park, Norwich NR4 7UQ, UK;
| | - Hector A. Bergonia
- Department of Internal Medicine, Division of Hematology, University of Utah, Salt Lake City, UT 84112, USA; (L.K.J.); (H.A.B.)
| | - Harry A. Dailey
- Department of Microbiology, Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA (H.A.D.)
| | - John D. Phillips
- Department of Internal Medicine, Division of Hematology, University of Utah, Salt Lake City, UT 84112, USA; (L.K.J.); (H.A.B.)
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Sebastiani F, Dali A, Alonso de Armiño DJ, Campagni L, Patil G, Becucci M, Hofbauer S, Estrin DA, Smulevich G. The role of the distal cavity in carbon monoxide stabilization in the coproheme decarboxylase enzyme from C. diphtheriae. J Inorg Biochem 2023; 245:112243. [PMID: 37196412 DOI: 10.1016/j.jinorgbio.2023.112243] [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: 03/03/2023] [Revised: 04/28/2023] [Accepted: 05/01/2023] [Indexed: 05/19/2023]
Abstract
This work focuses on the carbon monoxide adducts of the wild-type and selected variants of the coproheme decarboxylase from actinobacterial Corynebacterium diphtheriae complexed with coproheme, monovinyl monopropionyl deuteroheme (MMD), and heme b. The UV - vis and resonance Raman spectroscopies together with the molecular dynamics simulations clearly show that the wild-type coproheme-CO adduct is characterized by two CO conformers, one hydrogen-bonded to the distal H118 residue and the other showing a weak polar interaction with the distal cavity. Instead, upon conversion to heme b, i.e. after decarboxylation of propionates 2 and 4 and rotation by 90o of the porphyrin ring inside the cavity, CO probes a less polar environment. In the absence of the H118 residue, both coproheme and heme b complexes form only the non-H-bonded CO species. The unrotated MMD-CO adduct as observed in the H118F variant, confirms that decarboxylation of propionate 2 only, does not affect the heme cavity. The rupture of both the H-bonds involving propionates 2 and 4 destabilizes the porphyrin inside the cavity with the subsequent formation of a CO adduct in an open conformation. In addition, in this work we present data on CO binding to reversed heme b, obtained by hemin reconstitution of the H118A variant, and to heme d, obtained by addition of an excess of hydrogen peroxide. The results will be discussed and compared with those reported for the representatives of the firmicute clade.
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Affiliation(s)
- Federico Sebastiani
- Dipartimento di Chimica "Ugo Schiff" DICUS, Università di Firenze, Via della Lastruccia 3-13, Sesto Fiorentino (FI) I-50019, Italy
| | - Andrea Dali
- Dipartimento di Chimica "Ugo Schiff" DICUS, Università di Firenze, Via della Lastruccia 3-13, Sesto Fiorentino (FI) I-50019, Italy
| | - Diego Javier Alonso de Armiño
- CONICET-Universidad de Buenos Aires, Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), Buenos Aires, Argentina
| | - Lorenzo Campagni
- Dipartimento di Chimica "Ugo Schiff" DICUS, Università di Firenze, Via della Lastruccia 3-13, Sesto Fiorentino (FI) I-50019, Italy
| | - Gaurav Patil
- University of Natural Resources and Life Sciences, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, Vienna A-1190, Austria
| | - Maurizio Becucci
- Dipartimento di Chimica "Ugo Schiff" DICUS, Università di Firenze, Via della Lastruccia 3-13, Sesto Fiorentino (FI) I-50019, Italy.
| | - Stefan Hofbauer
- University of Natural Resources and Life Sciences, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, Vienna A-1190, Austria.
| | - Dario A Estrin
- CONICET-Universidad de Buenos Aires, Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), Buenos Aires, Argentina; Universidad de Buenos Aires, Departamento de Quimica Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Buenos Aires C1428EGA, Argentina.
| | - Giulietta Smulevich
- Dipartimento di Chimica "Ugo Schiff" DICUS, Università di Firenze, Via della Lastruccia 3-13, Sesto Fiorentino (FI) I-50019, Italy; INSTM Research Unit of Firenze, via della Lastruccia 3, Sesto Fiorentino I-50019, Italy.
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5
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Falb N, Patil G, Furtmüller PG, Gabler T, Hofbauer S. Structural aspects of enzymes involved in prokaryotic Gram-positive heme biosynthesis. Comput Struct Biotechnol J 2023; 21:3933-3945. [PMID: 37593721 PMCID: PMC10427985 DOI: 10.1016/j.csbj.2023.07.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/19/2023] [Accepted: 07/19/2023] [Indexed: 08/19/2023] Open
Abstract
The coproporphyrin dependent heme biosynthesis pathway is almost exclusively utilized by Gram-positive bacteria. This fact makes it a worthwhile topic for basic research, since a fundamental understanding of a metabolic pathway is necessary to translate the focus towards medical biotechnology, which is very relevant in this specific case, considering the need for new antibiotic targets to counteract the pathogenicity of Gram-positive superbugs. Over the years a lot of structural data on the set of enzymes acting in Gram-positive heme biosynthesis has accumulated in the Protein Database (www.pdb.org). One major challenge is to filter and analyze all available structural information in sufficient detail in order to be helpful and to draw conclusions. Here we pursued to give a holistic overview of structural information on enzymes involved in the coproporphyrin dependent heme biosynthesis pathway. There are many aspects to be extracted from experimentally determined structures regarding the reaction mechanisms, where the smallest variation of the position of an amino acid residue might be important, but also on a larger level regarding protein-protein interactions, where the focus has to be on surface characteristics and subunit (secondary) structural elements and oligomerization. This review delivers a status quo, highlights still missing information, and formulates future research endeavors in order to better understand prokaryotic heme biosynthesis.
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Affiliation(s)
- Nikolaus Falb
- University of Natural Resources and Life Sciences, Vienna, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, A-1190 Vienna, Austria
| | - Gaurav Patil
- University of Natural Resources and Life Sciences, Vienna, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, A-1190 Vienna, Austria
| | - Paul G. Furtmüller
- University of Natural Resources and Life Sciences, Vienna, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, A-1190 Vienna, Austria
| | - Thomas Gabler
- University of Natural Resources and Life Sciences, Vienna, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, A-1190 Vienna, Austria
| | - Stefan Hofbauer
- University of Natural Resources and Life Sciences, Vienna, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, A-1190 Vienna, Austria
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6
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Patil G, Michlits H, Furtmüller PG, Hofbauer S. Reactivity of Coproheme Decarboxylase with Monovinyl, Monopropionate Deuteroheme. Biomolecules 2023; 13:946. [PMID: 37371526 PMCID: PMC10296651 DOI: 10.3390/biom13060946] [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: 04/28/2023] [Revised: 05/23/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023] Open
Abstract
Coproheme decarboxylases (ChdCs) are terminal enzymes of the coproporphyrin-dependent heme biosynthetic pathway. In this reaction, two propionate groups are cleaved from the redox-active iron-containing substrate, coproheme, to form vinyl groups of the heme b product. The two decarboxylation reactions proceed sequentially, and a redox-active three-propionate porphyrin, called monovinyl, monopropionate deuteroheme (MMD), is transiently formed as an intermediate. While the reaction mechanism for the first part of the redox reaction, which is initiated by hydrogen peroxide, has been elucidated in some detail, the second part of this reaction, starting from MMD, has not been studied. Here, we report the optimization of enzymatic MMD production by ChdC and purification by reversed-phase chromatography. With the obtained MMD, we were able to study the second part of heme b formation by actinobacterial ChdC from Corynebacterium diphtheriae, starting with Compound I formation upon the addition of hydrogen peroxide. The results indicate that the second part of the decarboxylation reaction is analogous to the first part, although somewhat slower, which is explained by differences in the active site architecture and its H-bonding network. The results are discussed in terms of known kinetic and structural data and help to fill some mechanistic gaps in the overall reaction catalyzed by ChdCs.
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Affiliation(s)
| | | | | | - Stefan Hofbauer
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
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Ushimaru R, Lyu J, Abe I. Diverse enzymatic chemistry for propionate side chain cleavages in tetrapyrrole biosynthesis. J Ind Microbiol Biotechnol 2023; 50:kuad016. [PMID: 37422437 PMCID: PMC10548856 DOI: 10.1093/jimb/kuad016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 07/07/2023] [Indexed: 07/10/2023]
Abstract
Tetrapyrroles represent a unique class of natural products that possess diverse chemical architectures and exhibit a broad range of biological functions. Accordingly, they attract keen attention from the natural product community. Many metal-chelating tetrapyrroles serve as enzyme cofactors essential for life, while certain organisms produce metal-free porphyrin metabolites with biological activities potentially beneficial for the producing organisms and for human use. The unique properties of tetrapyrrole natural products derive from their extensively modified and highly conjugated macrocyclic core structures. Most of these various tetrapyrrole natural products biosynthetically originate from a branching point precursor, uroporphyrinogen III, which contains propionate and acetate side chains on its macrocycle. Over the past few decades, many modification enzymes with unique catalytic activities, and the diverse enzymatic chemistries employed to cleave the propionate side chains from the macrocycles, have been identified. In this review, we highlight the tetrapyrrole biosynthetic enzymes required for the propionate side chain removal processes and discuss their various chemical mechanisms. ONE-SENTENCE SUMMARY This mini-review describes various enzymes involved in the propionate side chain cleavages during the biosynthesis of tetrapyrrole cofactors and secondary metabolites.
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Affiliation(s)
- Richiro Ushimaru
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Jiaqi Lyu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ikuro Abe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
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Sebastiani F, Baroni C, Patil G, Dali A, Becucci M, Hofbauer S, Smulevich G. The Role of the Hydrogen Bond Network in Maintaining Heme Pocket Stability and Protein Function Specificity of C. diphtheriae Coproheme Decarboxylase. Biomolecules 2023; 13:235. [PMID: 36830604 PMCID: PMC9953210 DOI: 10.3390/biom13020235] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 01/27/2023] Open
Abstract
Monoderm bacteria accumulate heme b via the coproporphyrin-dependent biosynthesis pathway. In the final step, in the presence of two molecules of H2O2, the propionate groups of coproheme at positions 2 and 4 are decarboxylated to form vinyl groups by coproheme decarboxylase (ChdC), in a stepwise process. Decarboxylation of propionate 2 produces an intermediate that rotates by 90° inside the protein pocket, bringing propionate 4 near the catalytic tyrosine, to allow the second decarboxylation step. The active site of ChdCs is stabilized by an extensive H-bond network involving water molecules, specific amino acid residues, and the propionate groups of the porphyrin. To evaluate the role of these H-bonds in the pocket stability and enzyme functionality, we characterized, via resonance Raman and electronic absorption spectroscopies, single and double mutants of the actinobacterial pathogen Corynebacterium diphtheriae ChdC complexed with coproheme and heme b. The selective elimination of the H-bond interactions between propionates 2, 4, 6, and 7 and the polar residues of the pocket allowed us to establish the role of each H-bond in the catalytic reaction and to follow the changes in the interactions from the substrate to the product.
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Affiliation(s)
- Federico Sebastiani
- Dipartimento di Chimica “Ugo Schiff”, DICUS, Università di Firenze, Via della Lastruccia 3-13, I-50019 Sesto Fiorentino, Italy
| | - Chiara Baroni
- Dipartimento di Chimica “Ugo Schiff”, DICUS, Università di Firenze, Via della Lastruccia 3-13, I-50019 Sesto Fiorentino, Italy
| | - Gaurav Patil
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Andrea Dali
- Dipartimento di Chimica “Ugo Schiff”, DICUS, Università di Firenze, Via della Lastruccia 3-13, I-50019 Sesto Fiorentino, Italy
| | - Maurizio Becucci
- Dipartimento di Chimica “Ugo Schiff”, DICUS, Università di Firenze, Via della Lastruccia 3-13, I-50019 Sesto Fiorentino, Italy
| | - Stefan Hofbauer
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Giulietta Smulevich
- Dipartimento di Chimica “Ugo Schiff”, DICUS, Università di Firenze, Via della Lastruccia 3-13, I-50019 Sesto Fiorentino, Italy
- INSTM Research Unit of Firenze, via della Lastruccia 3, I-50019 Sesto Fiorentino, Italy
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Sebastiani F, Niccoli C, Michlits H, Risorti R, Becucci M, Hofbauer S, Smulevich G. Spectroscopic evidence of the effect of hydrogen peroxide excess on the coproheme decarboxylase from actinobacterial Corynebacterium diphtheriae. JOURNAL OF RAMAN SPECTROSCOPY : JRS 2022; 53:890-901. [PMID: 35910417 PMCID: PMC9310987 DOI: 10.1002/jrs.6326] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/15/2022] [Accepted: 02/23/2022] [Indexed: 05/29/2023]
Abstract
The actinobacterial coproheme decarboxylase from Corynebacterium diphtheriae catalyzes the final reaction to generate heme b via the "coproporphyrin-dependent" heme biosynthesis pathway in the presence of hydrogen peroxide. The enzyme has a high reactivity toward H2O2 used for the catalytic reaction and in the presence of an excess of H2O2 new species are generated. Resonance Raman data, together with electronic absorption spectroscopy and mass spectrometry, indicate that an excess of hydrogen peroxide for both the substrate (coproheme) and product (heme b) complexes of this enzyme causes a porphyrin hydroxylation of ring C or D, which is compatible with the formation of an iron chlorin-type heme d species. A similar effect has been previously observed for other heme-containing proteins, but this is the first time that a similar mechanism is reported for a coproheme enzyme. The hydroxylation determines a symmetry lowering of the porphyrin macrocycle, which causes the activation of A2g modes upon Soret excitation with a significant change in their polarization ratios, the enhancement and splitting into two components of many Eu bands, and an intensity decrease of the non-totally symmetric modes B1g, which become polarized. This latter effect is clearly observed for the isolated ν10 mode upon either Soret or Q-band excitations. The distal His118 is shown to be an absolute requirement for the conversion to heme d. This residue also plays an important role in the oxidative decarboxylation, because it acts as a base for deprotonation and subsequent heterolytic cleavage of hydrogen peroxide.
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Affiliation(s)
- Federico Sebastiani
- Dipartimento di Chimica “Ugo Schiff” DICUSUniversità di FirenzeSesto FiorentinoItaly
| | - Chiara Niccoli
- Dipartimento di Chimica “Ugo Schiff” DICUSUniversità di FirenzeSesto FiorentinoItaly
| | - Hanna Michlits
- Department of Chemistry, Institute of BiochemistryUniversity of Natural Resources and Life Sciences, ViennaViennaAustria
| | - Riccardo Risorti
- Dipartimento di Chimica “Ugo Schiff” DICUSUniversità di FirenzeSesto FiorentinoItaly
| | - Maurizio Becucci
- Dipartimento di Chimica “Ugo Schiff” DICUSUniversità di FirenzeSesto FiorentinoItaly
| | - Stefan Hofbauer
- Department of Chemistry, Institute of BiochemistryUniversity of Natural Resources and Life Sciences, ViennaViennaAustria
| | - Giulietta Smulevich
- Dipartimento di Chimica “Ugo Schiff” DICUSUniversità di FirenzeSesto FiorentinoItaly
- INSTM Research Unit of FirenzeSesto FiorentinoItaly
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10
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An active site at work – the role of key residues in C. diphteriae coproheme decarboxylase. J Inorg Biochem 2022; 229:111718. [DOI: 10.1016/j.jinorgbio.2022.111718] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/14/2021] [Accepted: 01/01/2022] [Indexed: 12/12/2022]
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11
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Reorienting Mechanism of Harderoheme in Coproheme Decarboxylase-A Computational Study. Int J Mol Sci 2022; 23:ijms23052564. [PMID: 35269706 PMCID: PMC8910490 DOI: 10.3390/ijms23052564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/16/2022] [Accepted: 02/23/2022] [Indexed: 02/06/2023] Open
Abstract
Coproheme decarboxylase (ChdC) is an important enzyme in the coproporphyrin-dependent pathway (CPD) of Gram-positive bacteria that decarboxylates coproheme on two propionates at position 2 and position 4 sequentially to generate heme b by using H2O2 as an oxidant. This work focused on the ChdC from Geobacillus stearothermophilus (GsChdC) to elucidate the mechanism of its sequential two-step decarboxylation of coproheme. The models of GsChdC in a complex with substrate and reaction intermediate were built to investigate the reorienting mechanism of harderoheme. Targeted molecular dynamics simulations on these models validated that harderoheme is able to rotate in the active site of GsChdC with a 19.06-kcal·mol-1 energy barrier after the first step of decarboxylation to bring the propionate at position 4 in proximity of Tyr145 to continue the second decarboxylation step. The harderoheme rotation mechanism is confirmed to be much easier than the release-rebinding mechanism. In the active site of GsChdC, Trp157 and Trp198 comprise a "gate" construction to regulate the clockwise rotation of the harderoheme. Lys149 plays a critical role in the rotation mechanism, which not only keeps the Trp157-Trp198 "gate" from being closed but also guides the propionate at position 4 through the gap between Trp157 and Trp198 through a salt bridge interaction.
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Michlits H, Valente N, Mlynek G, Hofbauer S. Initial Steps to Engineer Coproheme Decarboxylase to Obtain Stereospecific Monovinyl, Monopropionyl Deuterohemes. Front Bioeng Biotechnol 2022; 9:807678. [PMID: 35141216 PMCID: PMC8819088 DOI: 10.3389/fbioe.2021.807678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 12/29/2021] [Indexed: 11/13/2022] Open
Abstract
The oxidative decarboxylation of coproheme to form heme b by coproheme decarboxylase is a stereospecific two-step reaction. In the first step, the propionate at position two (p2) is cleaved off the pyrrole ring A to form a vinyl group at this position. Subsequently, the propionate at position four (p4) on pyrrole ring B is cleaved off and heme b is formed. In this study, we attempted to engineer coproheme decarboxylase from Corynebacterium diphtheriae to alter the stereospecificity of this reaction. By introducing a tyrosine residue in proximity to the propionate at position 4, we were able to create a new radical center in the active site. However, the artificial Tyr183• radical could not be shown to catalyze any decarboxylation.
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Affiliation(s)
- Hanna Michlits
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Nina Valente
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Georg Mlynek
- Core Facility Biomolecular and Cellular Analysis, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Stefan Hofbauer
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, Vienna, Austria
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