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Shalileh F, Gheibzadeh MS, Lloyd JR, Fietz S, Shahbani Zahiri H, Zolfaghari Emameh R. Evolutionary analysis and quality assessment of ζ-carbonic anhydrase sequences from environmental microbiome. J Basic Microbiol 2023; 63:1412-1425. [PMID: 37670218 DOI: 10.1002/jobm.202300323] [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: 06/10/2023] [Revised: 08/06/2023] [Accepted: 08/22/2023] [Indexed: 09/07/2023]
Abstract
Carbonic anhydrase (CA) is one of the most vital enzymes in living cells. This study has been performed due to the significance of this metalloenzyme for life and the novelty of some CA families like ζ-CA to evaluate evolutionary processes and quality check their sequences. In this study, bioinformatics methods revealed the presence of ζ-CA in some eukaryotic and prokaryotic microorganisms. Notably, it has not been previously reported in prokaryotes. The coexistence of β- and ζ-CAs in some microorganisms is also a novel finding as well. Also, our analysis identified several CA proteins with 6-14 amino acid intervals between histidine and cysteine in the second highly conserved motif, which can be classified as the novel ζ-CA subfamily members that emerged under the Zn deficiency of aquatic ecosystems and selection pressure in these environments. There is also a possibility that the achieved results are rooted in the contamination of samples from the environmental microbiome genome with genomes of diatom species and the occurrence of errors was observed in the DNA sequencing outcomes. Combining of all results from evolutionary analysis to quality control of ζ-CA DNA sequences is the incentive motivation to explore more the hidden aspects of ζ-CAs.
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Affiliation(s)
- Farzaneh Shalileh
- Department of Energy and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | - Mohammad S Gheibzadeh
- Department of Energy and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | - James R Lloyd
- Department of Genetics, Institute for Plant Biotechnology, University of Stellenbosch, Stellenbosch, South Africa
| | - Susanne Fietz
- Department of Earth Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - Hossein Shahbani Zahiri
- Department of Energy and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | - Reza Zolfaghari Emameh
- Department of Energy and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
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2
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Steger F, Reich J, Fuchs W, Rittmann SKMR, Gübitz GM, Ribitsch D, Bochmann G. Comparison of Carbonic Anhydrases for CO 2 Sequestration. Int J Mol Sci 2022; 23:957. [PMID: 35055147 PMCID: PMC8777876 DOI: 10.3390/ijms23020957] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/13/2022] [Accepted: 01/13/2022] [Indexed: 02/07/2023] Open
Abstract
Strategies for depleting carbon dioxide (CO2) from flue gases are urgently needed and carbonic anhydrases (CAs) can contribute to solving this problem. They catalyze the hydration of CO2 in aqueous solutions and therefore capture the CO2. However, the harsh conditions due to varying process temperatures are limiting factors for the application of enzymes. The current study aims to examine four recombinantly produced CAs from different organisms, namely CAs from Acetobacterium woodii (AwCA or CynT), Persephonella marina (PmCA), Methanobacterium thermoautotrophicum (MtaCA or Cab) and Sulphurihydrogenibium yellowstonense (SspCA). The highest expression yields and activities were found for AwCA (1814 WAU mg-1 AwCA) and PmCA (1748 WAU mg-1 PmCA). AwCA was highly stable in a mesophilic temperature range, whereas PmCA proved to be exceptionally thermostable. Our results indicate the potential to utilize CAs from anaerobic microorganisms to develop CO2 sequestration applications.
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Affiliation(s)
- Franziska Steger
- Institute of Environmental Biotechnology, Department for Agrobiotechnology, University of Natural Resources and Life Sciences Vienna, Konrad Lorenz Str. 20, A-3430 Tulln, Austria
| | - Johanna Reich
- Institute of Environmental Biotechnology, Department for Agrobiotechnology, University of Natural Resources and Life Sciences Vienna, Konrad Lorenz Str. 20, A-3430 Tulln, Austria
- ACIB-Austrian Centre of Industrial Biotechnology, Krenngasse 37, 8010 Graz, Austria
| | - Werner Fuchs
- Institute of Environmental Biotechnology, Department for Agrobiotechnology, University of Natural Resources and Life Sciences Vienna, Konrad Lorenz Str. 20, A-3430 Tulln, Austria
| | - Simon K-M R Rittmann
- Archaea Physiology & Biotechnology Group, Department of Functional and Evolutionary Ecology, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Georg M Gübitz
- Institute of Environmental Biotechnology, Department for Agrobiotechnology, University of Natural Resources and Life Sciences Vienna, Konrad Lorenz Str. 20, A-3430 Tulln, Austria
| | - Doris Ribitsch
- ACIB-Austrian Centre of Industrial Biotechnology, Krenngasse 37, 8010 Graz, Austria
| | - Günther Bochmann
- Institute of Environmental Biotechnology, Department for Agrobiotechnology, University of Natural Resources and Life Sciences Vienna, Konrad Lorenz Str. 20, A-3430 Tulln, Austria
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3
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Polishchuk OV. Stress-Related Changes in the Expression and Activity of Plant Carbonic Anhydrases. PLANTA 2021; 253:58. [PMID: 33532871 DOI: 10.1007/s00425-020-03553-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 12/23/2020] [Indexed: 05/17/2023]
Abstract
The data on stress-related changes in the expression and activity of plant carbonic anhydrases (CAs) suggest that they are generally upregulated at moderate stress severity. This indicates probable involvement of CAs in adaptation to drought, high salinity, heat, high light, Ci deficit, and excess bicarbonate. The changes in CA levels under cold stress are less studied and generally represented by the downregulation of CAs excepting βCA2. Excess Cd2+ and deficit of Zn2+ specifically reduce CA activity and reduce its synthesis. Probable roles of βCAs in stress adaptation include stomatal closure, ROS scavenging and partial compensation for decreased mesophyll CO2 conductance. βCAs play contrasting roles in pathogen responses, interacting with phytohormone signaling networks. Their role can be either negative or positive, probably depending on the host-pathogen system, pathogen initial titer, and levels of ·NO and ROS. It is still not clear why CAs are suppressed under severe stress levels. It should be noted, that the role of βCAs in the facilitation of CO2 diffusion and their involvement in redox signaling or ROS detoxication are potentially antagonistic, as they are inactivated by oxidation or nitrosylation. Interestingly, some chloroplastic βCAs may be relocated to the cytoplasm under stress conditions, but the physiological meaning of this effect remains to be studied.
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Affiliation(s)
- O V Polishchuk
- Membranology and Phytochemistry Department, M.G. Kholodny Institute of Botany of NAS of Ukraine, 2 Tereshchenkivska Str, Kyiv, 01004, Ukraine.
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4
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Combs JE, Andring JT, McKenna R. Neutron crystallographic studies of carbonic anhydrase. Methods Enzymol 2020; 634:281-309. [DOI: 10.1016/bs.mie.2020.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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5
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Langella E, Alterio V, D’Ambrosio K, Cadoni R, Winum JY, Supuran CT, Monti SM, De Simone G, Di Fiore A. Exploring benzoxaborole derivatives as carbonic anhydrase inhibitors: a structural and computational analysis reveals their conformational variability as a tool to increase enzyme selectivity. J Enzyme Inhib Med Chem 2019; 34:1498-1505. [PMID: 31423863 PMCID: PMC6713116 DOI: 10.1080/14756366.2019.1653291] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 07/31/2019] [Accepted: 08/02/2019] [Indexed: 12/22/2022] Open
Abstract
Recent studies identified the benzoxaborole moiety as a new zinc-binding group able to interact with carbonic anhydrase (CA) active site. Here, we report a structural analysis of benzoxaboroles containing urea/thiourea groups, showing that these molecules are very versatile since they can bind the enzyme assuming different binding conformations and coordination geometries of the catalytic zinc ion. In addition, theoretical calculations of binding free energy were performed highlighting the key role of specific residues for protein-inhibitor recognition. Overall, these data are very useful for the development of new inhibitors with higher selectivity and efficacy for various CAs.
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Affiliation(s)
- Emma Langella
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Naples, Italy
| | - Vincenzo Alterio
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Naples, Italy
| | - Katia D’Ambrosio
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Naples, Italy
| | - Roberta Cadoni
- Institut des Biomolécules Max Mousseron (IBMM) UMR 5247 CNRS, ENSCM, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier, Montpellier, France
- Dipartimento di Chimica e Farmacia, Università Degli Studi di Sassari, Sassari, Italy
| | - Jean-Yves Winum
- Institut des Biomolécules Max Mousseron (IBMM) UMR 5247 CNRS, ENSCM, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier, Montpellier, France
| | - Claudiu T. Supuran
- Neurofarba Department, Section of Pharmaceutical and Nutriceutical Sciences, Università Degli Studi di Firenze, Florence, Italy
| | - Simona Maria Monti
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Naples, Italy
| | - Giuseppina De Simone
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Naples, Italy
| | - Anna Di Fiore
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Naples, Italy
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6
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Murray AB, Aggarwal M, Pinard M, Vullo D, Patrauchan M, Supuran CT, McKenna R. Structural Mapping of Anion Inhibitors to β-Carbonic Anhydrase psCA3 from Pseudomonas aeruginosa. ChemMedChem 2018; 13:2024-2029. [PMID: 30088334 DOI: 10.1002/cmdc.201800375] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Indexed: 11/06/2022]
Abstract
Pseudomonas aeruginosa is a Gram-negative facultative anaerobe belonging to the Pseudomonadaceae family. It is a multidrug-resistant opportunistic human pathogen, a common cause of life-threatening nosocomial infections, and a key bacterial agent in cystic fibrosis and endocarditis. The bacterium exhibits intrinsic resistance to most antibacterial agents, including aminoglycosides and quinolones. Hence, the identification of new drug targets for P. aeruginosa is ongoing. PsCA3 is a β-class carbonic anhydrase (β-CA) that catalyzes the reversible hydration of carbon dioxide to bicarbonate and represents a new class of antimicrobial target. Previously, inhibitor screening studies of psCA3 have shown that a series of small anions including sulfamide (SFN), imidazole (IMD), and 4-methylimidazole (4MI), and thiocyanate (SCN) inhibit the enzyme with efficiencies in the micro- to millimolar range. Herein the X-ray crystal structures of these inhibitors in complex with psCA3 are presented and compared with human CA II. This structural survey into the binding modes of small anions forms the foundation for the development of inhibitors against β-CAs and more selective inhibitors against P. aeruginosa.
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Affiliation(s)
- Akilah B Murray
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Mayank Aggarwal
- Division of Biology and Soft Matter, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Melissa Pinard
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Daniela Vullo
- Università degli Studi di Firenze, Polo Scientifico, Dipartimento Neurofaba, Sezione di Scienze Farmaceutiche e Nutraceutiche, Via Ugo Schiff 6, 50019, Sesto Fiorentino, Firenze, Italy
| | - Marianna Patrauchan
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Claudiu T Supuran
- Università degli Studi di Firenze, Polo Scientifico, Dipartimento Neurofaba, Sezione di Scienze Farmaceutiche e Nutraceutiche, Via Ugo Schiff 6, 50019, Sesto Fiorentino, Firenze, Italy
| | - Robert McKenna
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
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Jin S, Sun J, Wunder T, Tang D, Cousins AB, Sze SK, Mueller-Cajar O, Gao YG. Structural insights into the LCIB protein family reveals a new group of β-carbonic anhydrases. Proc Natl Acad Sci U S A 2016; 113:14716-14721. [PMID: 27911826 PMCID: PMC5187666 DOI: 10.1073/pnas.1616294113] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Aquatic microalgae have evolved diverse CO2-concentrating mechanisms (CCMs) to saturate the carboxylase with its substrate, to compensate for the slow kinetics and competing oxygenation reaction of the key photosynthetic CO2-fixing enzyme rubisco. The limiting CO2-inducible B protein (LCIB) is known to be essential for CCM function in Chlamydomonas reinhardtii To assign a function to this previously uncharacterized protein family, we purified and characterized a phylogenetically diverse set of LCIB homologs. Three of the six homologs are functional carbonic anhydrases (CAs). We determined the crystal structures of LCIB and limiting CO2-inducible C protein (LCIC) from C. reinhardtii and a CA-functional homolog from Phaeodactylum tricornutum, all of which harbor motifs bearing close resemblance to the active site of canonical β-CAs. Our results identify the LCIB family as a previously unidentified group of β-CAs, and provide a biochemical foundation for their function in the microalgal CCMs.
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Affiliation(s)
- Shengyang Jin
- School of Biological Sciences, Nanyang Technological University, Singapore 637551
| | - Jian Sun
- School of Biological Sciences, Nanyang Technological University, Singapore 637551
| | - Tobias Wunder
- School of Biological Sciences, Nanyang Technological University, Singapore 637551
| | - Desong Tang
- School of Biological Sciences, Nanyang Technological University, Singapore 637551
- School of Agriculture and Food Science, Zhejiang A & F University, Hangzhou 311300, China
| | - Asaph B Cousins
- School of Biological Sciences, Washington State University, Pullman, WA 99163
| | - Siu Kwan Sze
- School of Biological Sciences, Nanyang Technological University, Singapore 637551
| | - Oliver Mueller-Cajar
- School of Biological Sciences, Nanyang Technological University, Singapore 637551;
| | - Yong-Gui Gao
- School of Biological Sciences, Nanyang Technological University, Singapore 637551;
- Institute of Molecular and Cell Biology, A*STAR, Singapore 138673
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8
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Zolfaghari Emameh R, Barker HR, Syrjänen L, Urbański L, Supuran CT, Parkkila S. Identification and inhibition of carbonic anhydrases from nematodes. J Enzyme Inhib Med Chem 2016; 31:176-184. [DOI: 10.1080/14756366.2016.1221826] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Reza Zolfaghari Emameh
- School of Medicine, University of Tampere, Tampere, Finland,
- BioMediTech, University of Tampere, Tampere, Finland,
- Fimlab Laboratories Ltd and Tampere University Hospital, Tampere, Finland,
| | | | - Leo Syrjänen
- School of Medicine, University of Tampere, Tampere, Finland,
- Department of Otorhinolaryngology, Central Finland Central Hospital, Jyväskylä, Finland, and
| | - Linda Urbański
- School of Medicine, University of Tampere, Tampere, Finland,
| | - Claudiu T. Supuran
- Neurofarba Dipartment, Sezione di Scienza Farmaceutiche e Nutraceutiche, Università degli Studi di Firenze, Firenze, Italy
| | - Seppo Parkkila
- School of Medicine, University of Tampere, Tampere, Finland,
- Fimlab Laboratories Ltd and Tampere University Hospital, Tampere, Finland,
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9
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Yao S, Flight RM, Rouchka EC, Moseley HNB. A less-biased analysis of metalloproteins reveals novel zinc coordination geometries. Proteins 2015; 83:1470-87. [PMID: 26009987 PMCID: PMC4539273 DOI: 10.1002/prot.24834] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 05/05/2015] [Accepted: 05/17/2015] [Indexed: 11/13/2022]
Abstract
Zinc metalloproteins are involved in many biological processes and play crucial biochemical roles across all domains of life. Local structure around the zinc ion, especially the coordination geometry (CG), is dictated by the protein sequence and is often directly related to the function of the protein. Current methodologies in characterizing zinc metalloproteins' CG consider only previously reported CG models based mainly on nonbiological chemical context. Exceptions to these canonical CG models are either misclassified or discarded as “outliers.” Thus, we developed a less‐biased method that directly handles potential exceptions without pre‐assuming any CG model. Our study shows that numerous exceptions could actually be further classified and that new CG models are needed to characterize them. Also, these new CG models are cross‐validated by strong correlation between independent structural and functional annotation distance metrics, which is partially lost if these new CGs models are ignored. Furthermore, these new CG models exhibit functional propensities distinct from the canonical CG models. Proteins 2015; 83:1470–1487. © 2015 The Authors. Proteins: Structure, Function, and Bioinformatics Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Sen Yao
- School of Interdisciplinary and Graduate Studies, University of Louisville, Louisville, Kentucky, 40292.,Department of Computer Engineering and Computer Science, University of Louisville, Louisville, Kentucky, 40292
| | - Robert M Flight
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, 40356.,Markey Cancer Center, University of Kentucky, Lexington, Kentucky, 40356.,Center for Environmental and Systems Biochemistry, University of Kentucky, Lexington, Kentucky, 40356
| | - Eric C Rouchka
- School of Interdisciplinary and Graduate Studies, University of Louisville, Louisville, Kentucky, 40292.,Department of Computer Engineering and Computer Science, University of Louisville, Louisville, Kentucky, 40292
| | - Hunter N B Moseley
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, 40356.,Markey Cancer Center, University of Kentucky, Lexington, Kentucky, 40356.,Center for Environmental and Systems Biochemistry, University of Kentucky, Lexington, Kentucky, 40356
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10
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Hoffmann KM, Million-Perez HR, Merkhofer R, Nicholson H, Rowlett RS. Allosteric reversion of Haemophilus influenzae β-carbonic anhydrase via a proline shift. Biochemistry 2015; 54:598-611. [PMID: 25506786 DOI: 10.1021/bi501116e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Haemophilus influenzae β-carbonic anhydrase (HICA) has been reverse-engineered in the allosteric site region to resemble the nonallosteric Pisum sativum enzyme in order to identify critical features of allostery and intersusbunit communication. Three variants (W39V/G41A, P48S/A49P, and W39V/G41A/P48S/A49P) were identified, through a comparison with a crystal structure of nonallosteric P. sativum β-carbonic anhydrase (PSCA, PDB 1EKJ ), to potentially revert HICA to a nonallosteric enzyme. The W39V/G41A and P48S/A49P mutations decreased the apparent kcat/Km proton dependence from 4 to 2 and 1, respectively, increasing the overall maximal kcat/Km to 16 ± 2 μM(-1) s(-1) (380% of wild type) and 17 ± 3 μM(-1) s(-1) (405% of wild type). The pKa values of the metal-bound water molecule based on the pH-rate profile kinetics (8.32 ± 0.04 for W39V/G41A and 8.3 ± 0.1 for P48S/A49P) were also slightly higher than that for the wild-type enzyme (7.74 ± 0.04). The P48S/A49P variant has lost all pH-rate cooperativity. The W39V/G41A/P48S/A49P variant's kinetics were unusual and were fit with a log-linear function with a slope 0.9 ± 0.2. The crystal structure of the W39V/G41A variant revealed an active site very similar to the T-state wild-type oligomer with bicarbonate trapped in the escort site. By contrast, the X-ray crystal structure of a proline shift variant (P48S/A49P) reveals that it has adopted an active site conformation nearly identical to that of nonallosteric β-carbonic anhydrase (R-state) for one chain, including a tight association with the dimer-exchanged N-terminal helices; the second chain in the asymmetric unit is associated in a biologically relevant oligomer, but it adopts a T-state conformation that is not capped by dimer-exchanged N-terminal helices. The hybrid R/T nature of HICA P48S/A49P structurally recapitulates the interruption of pH-rate cooperativity observed for this variant. Comparison of the conformations of the R and T chains of P48S/A49P suggests a new hypothesis to explain HICA allosteric communication that is mediated by the N-terminal helices and anion binding at the dimer interface.
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Affiliation(s)
- Katherine M Hoffmann
- Department of Chemistry, Gonzaga University , 502 East Boone Avenue, Spokane, Washington 99258, United States
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11
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Lehneck R, Neumann P, Vullo D, Elleuche S, Supuran CT, Ficner R, Pöggeler S. Crystal structures of two tetrameric β-carbonic anhydrases from the filamentous ascomycete Sordaria macrospora. FEBS J 2014; 281:1759-72. [PMID: 24506675 DOI: 10.1111/febs.12738] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 01/30/2014] [Accepted: 01/31/2014] [Indexed: 01/11/2023]
Abstract
UNLABELLED Carbonic anhydrases (CAs) are metalloenzymes catalyzing the reversible hydration of carbon dioxide to bicarbonate (hydrogen carbonate) and protons. CAs have been identified in archaea, bacteria and eukaryotes and can be classified into five groups (α, β, γ, δ, ζ) that are unrelated in sequence and structure. The fungal β-class has only recently attracted attention. In the present study, we investigated the structure and function of the plant-like β-CA proteins CAS1 and CAS2 from the filamentous ascomycete Sordaria macrospora. We demonstrated that both proteins can substitute for the Saccharomyces cerevisiae β-CA Nce103 and exhibit an in vitro CO2 hydration activity (kcat /Km of CAS1: 1.30 × 10(6) m(-1) ·s(-1) ; CAS2: 1.21 × 10(6 ) m(-1) ·s(-1) ). To further investigate the structural properties of CAS1 and CAS2, we determined their crystal structures to a resolution of 2.7 Å and 1.8 Å, respectively. The oligomeric state of both proteins is tetrameric. With the exception of the active site composition, no further major differences have been found. In both enzymes, the Zn(2) (+) -ion is tetrahedrally coordinated; in CAS1 by Cys45, His101 and Cys104 and a water molecule and in CAS2 by the side chains of four residues (Cys56, His112, Cys115 and Asp58). Both CAs are only weakly inhibited by anions, making them good candidates for industrial applications. STRUCTURED DIGITAL ABSTRACT CAS1 and CAS2 bind by x-ray crystallography (View interaction) DATABASE Structural data have been deposited in the Protein Data Bank database under accession numbers 4O1J for CAS1 and 4O1K for CAS2.
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Affiliation(s)
- Ronny Lehneck
- Institute of Microbiology and Genetics, Department of Genetics of Eukaryotic Microorganisms, Georg-August-University Göttingen, Germany
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