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Liu B, Wang W, Qiu J, Huang X, Qiu S, Bao Y, Xu S, Ruan L, Ran T, He J. Crystal structures of herbicide-detoxifying esterase reveal a lid loop affecting substrate binding and activity. Nat Commun 2023; 14:4343. [PMID: 37468532 DOI: 10.1038/s41467-023-40103-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 07/11/2023] [Indexed: 07/21/2023] Open
Abstract
SulE, an esterase, which detoxifies a variety of sulfonylurea herbicides through de-esterification, provides an attractive approach to remove environmental sulfonylurea herbicides and develop herbicide-tolerant crops. Here, we determined the crystal structures of SulE and an activity improved mutant P44R. Structural analysis revealed that SulE is a dimer with spacious binding pocket accommodating the large sulfonylureas substrate. Particularly, SulE contains a protruding β hairpin with a lid loop covering the active site of the other subunit of the dimer. The lid loop participates in substrate recognition and binding. P44R mutation altered the lid loop flexibility, resulting in the sulfonylurea heterocyclic ring repositioning to a relative stable conformation thus leading to dramatically increased activity. Our work provides important insights into the molecular mechanism of SulE, and establish a solid foundation for further improving the enzyme activity to various sulfonylurea herbicides through rational design.
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Affiliation(s)
- Bin Liu
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
- College of Life Sciences, Jiangxi Normal University, Nanchang, 330022, China
| | - Weiwu Wang
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jiguo Qiu
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xing Huang
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shenshen Qiu
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yixuan Bao
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Siqiong Xu
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Luyao Ruan
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Tingting Ran
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Jian He
- Key Laboratory of Agricultural Environmental Microbiology of Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
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2
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Soumya P, Kochupurackal J. An Esterase with Increased Acetone Tolerance from Bacillus subtilis E9 over Expressed in E. coli BL21 Using pTac Bs-est Vector. Mol Biotechnol 2022; 64:814-824. [PMID: 35137334 DOI: 10.1007/s12033-022-00458-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 01/30/2022] [Indexed: 02/06/2023]
Abstract
Bacillus subtilis E9 was identified as a potential strain producing esterase. The gene coding esterase from B. subtilis E9 was amplified using esterase-specific primers and the sequence was translated in silico. The presence of conserved catalytic triad amino acid residues (His-Ser-Asp/Glu) confirmed the functional nature of the esterase enzyme. Docking studies conducted with modeled protein and the ligand p-nitrophenyl acetate showed that the amino acid residues interacting with the ligand were Ser77, His76, and Gly103. The gene coding for esterase from B. subtilis E9 was cloned into an assembled vector having Tac promoter (pTac), pUC origin of replication, Ni-Histidine residues, ampicillin cassette, and T7 terminator using Golden gate DNA assembly method. The generated pTac Bs-est (4598 bp) recombinant plasmid was transformed and heterologously expressed in Escherichia coli BL21 (DE3) strain. The tagged recombinant protein was purified to yield 43.4% pure protein with specific activity of 772 U/mg. The purified recombinant protein was subjected to peptide sequencing and the identity was confirmed as esterase by peptide tandem mass fragmentation method using the LC-MS/MS analysis. The purified recombinant esterase was found to be organic solvent stable and tolerant up to 5 days retaining around 95% residual activity in 30-90% v/v Acetone. The recombinant esterase expressed in our study was found to exhibit better organic solvent stability and tolerance than compared to the original bacterial esterase from B. subtilis E9, a property which could be explored in the biocatalytic and synthetic transformation reactions for industrial applications.
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Affiliation(s)
- P Soumya
- School of Biosciences, Mahatma Gandhi University, Kottayam, Kerala, 686560, India
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3
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Denesyuk A, Dimitriou PS, Johnson MS, Nakayama T, Denessiouk K. The acid-base-nucleophile catalytic triad in ABH-fold enzymes is coordinated by a set of structural elements. PLoS One 2020; 15:e0229376. [PMID: 32084230 PMCID: PMC7034887 DOI: 10.1371/journal.pone.0229376] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 02/05/2020] [Indexed: 01/09/2023] Open
Abstract
The alpha/beta-Hydrolases (ABH) are a structural class of proteins that are found widespread in nature and includes enzymes that can catalyze various reactions in different substrates. The catalytic versatility of the ABH fold enzymes, which has been a valuable property in protein engineering applications, is based on a similar acid-base-nucleophile catalytic mechanism. In our research, we are concerned with the structure that surrounds the key units of the catalytic machinery, and we have previously found conserved structural organizations that coordinate the catalytic acid, the catalytic nucleophile and the residues of the oxyanion hole. Here, we explore the architecture that surrounds the catalytic histidine at the active sites of enzymes from 40 ABH fold families, where we have identified six conserved interactions that coordinate the catalytic histidine next to the catalytic acid and the catalytic nucleophile. Specifically, the catalytic nucleophile is coordinated next to the catalytic histidine by two weak hydrogen bonds, while the catalytic acid is directly involved in the coordination of the catalytic histidine through by two weak hydrogen bonds. The imidazole ring of the catalytic histidine is coordinated by a CH-π contact and a hydrophobic interaction. Moreover, the catalytic triad residues are connected with a residue that is located at the core of the active site of ABH fold, which is suggested to be the fourth member of a “structural catalytic tetrad”. Besides their role in the stability of the catalytic mechanism, the conserved elements of the catalytic site are actively involved in ligand binding and affect other properties of the catalytic activity, such as substrate specificity, enantioselectivity, pH optimum and thermostability of ABH fold enzymes. These properties are regularly targeted in protein engineering applications, and thus, the identified conserved structural elements can serve as potential modification sites in order to develop ABH fold enzymes with altered activities.
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Affiliation(s)
- Alexander Denesyuk
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, Pushchino, Russia
- * E-mail:
| | - Polytimi S. Dimitriou
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Mark S. Johnson
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Toru Nakayama
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi, Japan
| | - Konstantin Denessiouk
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
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4
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Prisant MG, Williams CJ, Chen VB, Richardson JS, Richardson DC. New tools in MolProbity validation: CaBLAM for CryoEM backbone, UnDowser to rethink "waters," and NGL Viewer to recapture online 3D graphics. Protein Sci 2020; 29:315-329. [PMID: 31724275 PMCID: PMC6933861 DOI: 10.1002/pro.3786] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 12/17/2022]
Abstract
The MolProbity web service provides macromolecular model validation to help correct local errors, for the structural biology community worldwide. Here we highlight new validation features, and also describe how we are fighting back against outside developments which compromise that mission. Our new tool called UnDowser analyzes the properties and context of clashing HOH "waters" to diagnose what they might actually represent; a dozen distinct scenarios are illustrated and described. We now treat alternate conformations more thoroughly, and switching to the Neo4j database (graphical rather than relational) enables cleaner, more comprehensive, and much larger reference datasets. A problematic outside change is that refinement software now increasingly restrains traditional validation criteria (geometry, clashes, rotamers, and even Ramachandran) in order to supplement the sparser experimental data at 3-4 Å resolutions typical of modern cryoEM. But unfortunately the broad density allows model optimization without fixing underlying problems, which means these structures often score much better on validation than they really are. CaBLAM, our tool designed for evaluating peptide orientations at lower resolutions, was described in the previous Tools issue, and here we demonstrate its effectiveness in diagnosing local errors even when other validation outliers have been artificially removed. Sophisticated hacking of the MolProbity server has required continual monitoring and various security measures short of restricting user access. The deprecation of Java applets now prevents KiNG interactive online display of outliers on the 3D model during a MolProbity run, but that important functionality has now been recaptured with a modified version of the Javascript NGL Viewer.
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Affiliation(s)
- Michael G. Prisant
- Department of BiochemistryDuke University Medical CenterDurhamNorth Carolina
| | | | - Vincent B. Chen
- Department of BiochemistryDuke University Medical CenterDurhamNorth Carolina
| | - Jane S. Richardson
- Department of BiochemistryDuke University Medical CenterDurhamNorth Carolina
| | - David C. Richardson
- Department of BiochemistryDuke University Medical CenterDurhamNorth Carolina
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5
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Liu B, Peng Q, Sheng M, Hu S, Qian M, Fan B, He J. Directed Evolution of Sulfonylurea Esterase and Characterization of a Variant with Improved Activity. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:836-843. [PMID: 30585487 DOI: 10.1021/acs.jafc.8b06198] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Esterase SulE detoxicates a variety of sulfonylurea herbicides through de-esterification. SulE exhibits high activity against thifensulfuron-methyl but low activity against other sulfonylureas. In this study, two variants, m2311 (P80R) and m0569 (P80R and G176A), with improved activity were screened from a mutation library constructed by error-prone PCR. Variant m2311 showed a higher activity against sulfonylureas in comparison variant m0569 and was further investigated. The kcat/ Km value of variant m2311 for metsulfuron-methyl, sulfometuron-methyl, chlorimuron-ethyl, tribenuron-methyl, and ethametsulfuron-methyl increased by 3.20-, 1.72-, 2.94-, 2.26- and 2.96-fold, respectively, in comparison with the wild type. Molecular modeling suggested that the activity improvement of variant m2311 is due to the substitution of Pro80 by arginine, leading to the formation of new hydrogen bonds between the enzyme and substrate. This study facilitates further elucidation of the structure and function of SulE and provides an improved gene resource for the detoxification of sulfonylurea residues and the genetic engineering of sulfonylurea-resistant crops.
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Affiliation(s)
- Bin Liu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences , Nanjing Agricultural University , Nanjing 210095 , Jiangsu , People's Republic of China
| | - Qian Peng
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences , Nanjing Agricultural University , Nanjing 210095 , Jiangsu , People's Republic of China
| | - Mengyao Sheng
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences , Nanjing Agricultural University , Nanjing 210095 , Jiangsu , People's Republic of China
| | - Shishan Hu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences , Nanjing Agricultural University , Nanjing 210095 , Jiangsu , People's Republic of China
| | - Meng Qian
- Laboratory Centre of Life Science, College of Life Sciences , Nanjing Agricultural University , Nanjing 210095 , Jiangsu , People's Republic of China
| | - Ben Fan
- College of Forest Resources and Environment , Nanjing Forestry University , Nanjing , Jiangsu , People's Republic of China
| | - Jian He
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences , Nanjing Agricultural University , Nanjing 210095 , Jiangsu , People's Republic of China
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6
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Dimitriou PS, Denesyuk AI, Nakayama T, Johnson MS, Denessiouk K. Distinctive structural motifs co-ordinate the catalytic nucleophile and the residues of the oxyanion hole in the alpha/beta-hydrolase fold enzymes. Protein Sci 2018; 28:344-364. [PMID: 30311984 DOI: 10.1002/pro.3527] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/04/2018] [Accepted: 10/08/2018] [Indexed: 12/17/2022]
Abstract
The alpha/beta-hydrolases (ABH) are among the largest structural families of proteins that are found in nature. Although they vary in their sequence and function, the ABH enzymes use a similar acid-base-nucleophile catalytic mechanism to catalyze reactions on different substrates. Because ABH enzymes are biocatalysts with a wide range of potential applications, protein engineering has taken advantage of their catalytic versatility to develop enzymes with industrial applications. This study is a comprehensive analysis of 40 ABH enzyme families focusing on two identified substructures: the nucleophile zone and the oxyanion zone, which co-ordinate the catalytic nucleophile and the residues of the oxyanion hole, and independently reported as critical for the enzymatic activity. We also frequently observed an aromatic cluster near the nucleophile and oxyanion zones, and opposite the ligand-binding site. The nucleophile zone, the oxyanion zone and the residue cluster enriched in aromatic side chains comprise a three-dimensional structural organization that shapes the active site of ABH enzymes and plays an important role in the enzymatic function by structurally stabilizing the catalytic nucleophile and the residues of the oxyanion hole. The structural data support the notion that the aromatic cluster can participate in co-ordination of the catalytic histidine loop, and properly place the catalytic histidine next to the catalytic nucleophile.
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Affiliation(s)
- Polytimi S Dimitriou
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, 20520, Finland
| | - Alexander I Denesyuk
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, 20520, Finland.,Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, 142290, Russia
| | - Toru Nakayama
- Tohoku University, Biomolecular Engineering, Sendai, Miyagi, 980-8579, Japan
| | - Mark S Johnson
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, 20520, Finland
| | - Konstantin Denessiouk
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, 20520, Finland.,Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Pharmacy, Åbo Akademi University, Turku, 20520, Finland
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7
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Dimitriou PS, Denesyuk A, Takahashi S, Yamashita S, Johnson MS, Nakayama T, Denessiouk K. Alpha/beta-hydrolases: A unique structural motif coordinates catalytic acid residue in 40 protein fold families. Proteins 2017. [DOI: 10.1002/prot.25338] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Polytimi S. Dimitriou
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering; Åbo Akademi University; Turku 20520 Finland
| | - Alexander Denesyuk
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering; Åbo Akademi University; Turku 20520 Finland
- Institute for Biological Instrumentation of the Russian Academy of Sciences; Pushchino 142290 Russia
| | - Seiji Takahashi
- Department of Biomolecular Engineering, Graduate School of Engineering; Tohoku University; Sendai Miyagi 980-8579 Japan
| | - Satoshi Yamashita
- Division of Material Chemistry, Graduate School of Natural Science and Technology; Kanazawa University; Kanazawa Ishikawa 920-1192 Japan
| | - Mark S. Johnson
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering; Åbo Akademi University; Turku 20520 Finland
| | - Toru Nakayama
- Department of Biomolecular Engineering, Graduate School of Engineering; Tohoku University; Sendai Miyagi 980-8579 Japan
| | - Konstantin Denessiouk
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering; Åbo Akademi University; Turku 20520 Finland
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8
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Littlechild JA. Improving the 'tool box' for robust industrial enzymes. J Ind Microbiol Biotechnol 2017; 44:711-720. [PMID: 28401315 PMCID: PMC5408032 DOI: 10.1007/s10295-017-1920-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 02/05/2017] [Indexed: 01/31/2023]
Abstract
The speed of sequencing of microbial genomes and metagenomes is providing an ever increasing resource for the identification of new robust biocatalysts with industrial applications for many different aspects of industrial biotechnology. Using 'natures catalysts' provides a sustainable approach to chemical synthesis of fine chemicals, general chemicals such as surfactants and new consumer-based materials such as biodegradable plastics. This provides a sustainable and 'green chemistry' route to chemical synthesis which generates no toxic waste and is environmentally friendly. In addition, enzymes can play important roles in other applications such as carbon dioxide capture, breakdown of food and other waste streams to provide a route to the concept of a 'circular economy' where nothing is wasted. The use of improved bioinformatic approaches and the development of new rapid enzyme activity screening methodology can provide an endless resource for new robust industrial biocatalysts.This mini-review will discuss several recent case studies where industrial enzymes of 'high priority' have been identified and characterised. It will highlight specific hydrolase enzymes and recent case studies which have been carried out within our group in Exeter.
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Affiliation(s)
- J A Littlechild
- Henry Wellcome Building for Biocatalysis, Biosciences, College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK.
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9
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Richardson JS, Videau LL, Williams CJ, Richardson DC. Broad Analysis of Vicinal Disulfides: Occurrences, Conformations with Cis or with Trans Peptides, and Functional Roles Including Sugar Binding. J Mol Biol 2017; 429:1321-1335. [PMID: 28336403 DOI: 10.1016/j.jmb.2017.03.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 03/12/2017] [Accepted: 03/13/2017] [Indexed: 10/19/2022]
Abstract
Vicinal disulfides between sequence-adjacent cysteine residues are very rare and rather startling structural features which play a variety of functional roles. Typically discussed as an isolated curiosity, they have never received a general treatment covering both cis and trans forms. Enabled by the growing database of high-resolution structures, required deposition of diffraction data, and improved methods for discriminating reliable from dubious cases, we identify and describe distinct protein families with reliably genuine examples of cis or trans vicinal disulfides and discuss their conformations, conservation, and functions. No cis-trans interconversions and only one case of catalytic redox function are seen. Some vicinal disulfides are essential to large, functionally coupled motions, whereas most form the centers of tightly packed internal regions. Their most widespread biological role is providing a rigid hydrophobic contact surface under the undecorated side of a sugar or multiring ligand, contributing an important aspect of binding specificity.
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Affiliation(s)
- Jane S Richardson
- Department of Biochemistry, 3711 Duke University Medical Center, Durham, NC 27710, USA.
| | - Lizbeth L Videau
- Department of Biochemistry, 3711 Duke University Medical Center, Durham, NC 27710, USA
| | | | - David C Richardson
- Department of Biochemistry, 3711 Duke University Medical Center, Durham, NC 27710, USA
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Structural and biochemical characterisation of Archaeoglobus fulgidus esterase reveals a bound CoA molecule in the vicinity of the active site. Sci Rep 2016; 6:25542. [PMID: 27160974 PMCID: PMC4861933 DOI: 10.1038/srep25542] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 04/18/2016] [Indexed: 11/28/2022] Open
Abstract
A new carboxyl esterase, AF-Est2, from the hyperthermophilic archaeon Archaeoglobus fulgidus has been cloned, over-expressed in Escherichia coli and biochemically and structurally characterized. The enzyme has high activity towards short- to medium-chain p-nitrophenyl carboxylic esters with optimal activity towards the valerate ester. The AF-Est2 has good solvent and pH stability and is very thermostable, showing no loss of activity after incubation for 30 min at 80 °C. The 1.4 Å resolution crystal structure of AF-Est2 reveals Coenzyme A (CoA) bound in the vicinity of the active site. Despite the presence of CoA bound to the AF-Est2 this enzyme has no CoA thioesterase activity. The pantetheine group of CoA partially obstructs the active site alcohol pocket suggesting that this ligand has a role in regulation of the enzyme activity. A comparison with closely related α/β hydrolase fold enzyme structures shows that the AF-Est2 has unique structural features that allow CoA binding. A comparison of the structure of AF-Est2 with the human carboxyl esterase 1, which has CoA thioesterase activity, reveals that CoA is bound to different parts of the core domain in these two enzymes and approaches the active site from opposite directions.
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11
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Sayer C, Szabo Z, Isupov MN, Ingham C, Littlechild JA. The Structure of a Novel Thermophilic Esterase from the Planctomycetes Species, Thermogutta terrifontis Reveals an Open Active Site Due to a Minimal 'Cap' Domain. Front Microbiol 2015; 6:1294. [PMID: 26635762 PMCID: PMC4655241 DOI: 10.3389/fmicb.2015.01294] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 11/06/2015] [Indexed: 11/29/2022] Open
Abstract
A carboxyl esterase (TtEst2) has been identified in a novel thermophilic bacterium, Thermogutta terrifontis from the phylum Planctomycetes and has been cloned and over-expressed in Escherichia coli. The enzyme has been characterized biochemically and shown to have activity toward small p-nitrophenyl (pNP) carboxylic esters with optimal activity for pNP-acetate. The enzyme shows moderate thermostability retaining 75% activity after incubation for 30 min at 70°C. The crystal structures have been determined for the native TtEst2 and its complexes with the carboxylic acid products propionate, butyrate, and valerate. TtEst2 differs from most enzymes of the α/β-hydrolase family 3 as it lacks the majority of the ‘cap’ domain and its active site cavity is exposed to the solvent. The bound ligands have allowed the identification of the carboxyl pocket in the enzyme active site. Comparison of TtEst2 with structurally related enzymes has given insight into how differences in their substrate preference can be rationalized based upon the properties of their active site pockets.
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Affiliation(s)
- Christopher Sayer
- The Henry Wellcome Building for Biocatalysis, Biosciences, College of Life and Environmental Sciences, University of Exeter Exeter, UK
| | | | - Michail N Isupov
- The Henry Wellcome Building for Biocatalysis, Biosciences, College of Life and Environmental Sciences, University of Exeter Exeter, UK
| | | | - Jennifer A Littlechild
- The Henry Wellcome Building for Biocatalysis, Biosciences, College of Life and Environmental Sciences, University of Exeter Exeter, UK
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12
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Sayer C, Isupov MN, Bonch-Osmolovskaya E, Littlechild JA. Structural studies of a thermophilic esterase from a new Planctomycetes species, Thermogutta terrifontis. FEBS J 2015; 282:2846-57. [PMID: 26011036 DOI: 10.1111/febs.13326] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 05/08/2015] [Accepted: 05/19/2015] [Indexed: 11/28/2022]
Abstract
Thermogutta terrifontis esterase (TtEst), a carboxyl esterase identified in the novel thermophilic bacterium T. terrifontis from the phylum Planctomycetes, has been cloned and over-expressed in Escherichia coli. The enzyme has been characterized biochemically and shown to have activity towards small p-nitrophenyl (pNP) carboxylic esters, with optimal activity for pNP-propionate. The enzyme retained 95% activity after incubation for 1 h at 80 °C. The crystal structures of the native TtEst and its complexes with the substrate analogue D-malate and the product acetate have been determined to high resolution. The bound ligands have allowed the identification of the carboxyl and alcohol binding pockets in the enzyme active site. Comparison of TtEst with structurally related enzymes provides insight into how differences in their catalytic activity can be rationalized based upon the properties of the amino acid residues in their active site pockets. The mutant enzymes L37A and L251A have been constructed to extend the substrate range of TtEst towards the larger butyrate and valerate pNP-esters. These mutant enzymes have also shown a significant increase in activity towards acetate and propionate pNP esters. A crystal structure of the L37A mutant was determined with the butyrate product bound in the carboxyl pocket of the active site. The mutant structure shows an expansion of the pocket that binds the substrate carboxyl group, which is consistent with the observed increase in activity towards pNP-butyrate.
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Affiliation(s)
- Christopher Sayer
- The Henry Wellcome Building for Biocatalysis, Biosciences, College of Life and Environmental Sciences, University of Exeter, UK
| | - Michail N Isupov
- The Henry Wellcome Building for Biocatalysis, Biosciences, College of Life and Environmental Sciences, University of Exeter, UK
| | | | - Jennifer A Littlechild
- The Henry Wellcome Building for Biocatalysis, Biosciences, College of Life and Environmental Sciences, University of Exeter, UK
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13
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Rozeboom HJ, Godinho LF, Nardini M, Quax WJ, Dijkstra BW. Crystal structures of two Bacillus carboxylesterases with different enantioselectivities. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1844:567-75. [PMID: 24418394 DOI: 10.1016/j.bbapap.2014.01.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 01/02/2014] [Accepted: 01/05/2014] [Indexed: 01/08/2023]
Abstract
Naproxen esterase (NP) from Bacillus subtilis Thai I-8 is a carboxylesterase that catalyzes the enantioselective hydrolysis of naproxenmethylester to produce S-naproxen (E>200). It is a homolog of CesA (98% sequence identity) and CesB (64% identity), both produced by B. subtilis strain 168. CesB can be used for the enantioselective hydrolysis of 1,2-O-isopropylideneglycerol (solketal) esters (E>200 for IPG-caprylate). Crystal structures of NP and CesB, determined to a resolution of 1.75Å and 2.04Å, respectively, showed that both proteins have a canonical α/β hydrolase fold with an extra N-terminal helix stabilizing the cap subdomain. The active site in both enzymes is located in a deep hydrophobic groove and includes the catalytic triad residues Ser130, His274, and Glu245. A product analog, presumably 2-(2-hydroxyethoxy)acetic acid, was bound in the NP active site. The enzymes have different enantioselectivities, which previously were shown to result from only a few amino acid substitutions in the cap domain. Modeling of a substrate in the active site of NP allowed explaining the different enantioselectivities. In addition, Ala156 may be a determinant of enantioselectivity as well, since its side chain appears to interfere with the binding of certain R-enantiomers in the active site of NP. However, the exchange route for substrate and product between the active site and the solvent is not obvious from the structures. Flexibility of the cap domain might facilitate such exchange. Interestingly, both carboxylesterases show higher structural similarity to meta-cleavage compound (MCP) hydrolases than to other α/β hydrolase fold esterases.
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Affiliation(s)
- Henriëtte J Rozeboom
- Laboratory of Biophysical Chemistry, Centre of Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Luis F Godinho
- Department of Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713AV Groningen, The Netherlands
| | - Marco Nardini
- Laboratory of Biophysical Chemistry, Centre of Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Wim J Quax
- Department of Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713AV Groningen, The Netherlands
| | - Bauke W Dijkstra
- Laboratory of Biophysical Chemistry, Centre of Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
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SulE, a sulfonylurea herbicide de-esterification esterase from Hansschlegelia zhihuaiae S113. Appl Environ Microbiol 2012; 78:1962-8. [PMID: 22247165 DOI: 10.1128/aem.07440-11] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
De-esterification is an important degradation or detoxification mechanism of sulfonylurea herbicide in microbes and plants. However, the biochemical and molecular mechanisms of sulfonylurea herbicide de-esterification are still unknown. In this study, a novel esterase gene, sulE, responsible for sulfonylurea herbicide de-esterification, was cloned from Hansschlegelia zhihuaiae S113. The gene contained an open reading frame of 1,194 bp, and a putative signal peptide at the N terminal was identified with a predicted cleavage site between Ala37 and Glu38, resulting in a 361-residue mature protein. SulE minus the signal peptide was synthesized in Escherichia coli BL21 and purified to homogeneity. SulE catalyzed the de-esterification of a variety of sulfonylurea herbicides that gave rise to the corresponding herbicidally inactive parent acid and exhibited the highest catalytic efficiency toward thifensulfuron-methyl. SulE was a dimer without the requirement of a cofactor. The activity of the enzyme was completely inhibited by Ag(+), Cd(2+), Zn(2+), methamidophos, and sodium dodecyl sulfate. A sulE-disrupted mutant strain, ΔsulE, was constructed by insertion mutation. ΔsulE lost the de-esterification ability and was more sensitive to the herbicides than the wild type of strain S113, suggesting that sulE played a vital role in the sulfonylurea herbicide resistance of the strain. The transfer of sulE into Saccharomyces cerevisiae BY4741 conferred on it the ability to de-esterify sulfonylurea herbicides and increased its resistance to the herbicides. This study has provided an excellent candidate for the mechanistic study of sulfonylurea herbicide metabolism and detoxification through de-esterification, construction of sulfonylurea herbicide-resistant transgenic crops, and bioremediation of sulfonylurea herbicide-contaminated environments.
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15
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Stehle F, Brandt W, Stubbs MT, Milkowski C, Strack D. Sinapoyltransferases in the light of molecular evolution. PHYTOCHEMISTRY 2009; 70:1652-62. [PMID: 19695650 DOI: 10.1016/j.phytochem.2009.07.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Revised: 07/07/2009] [Accepted: 07/16/2009] [Indexed: 05/08/2023]
Abstract
Acylation is a prevalent chemical modification that to a significant extent accounts for the tremendous diversity of plant metabolites. To catalyze acyl transfer reactions, higher plants have evolved acyltransferases that accept beta-acetal esters, typically 1-O-glucose esters, as an alternative to the ubiquitously occurring CoA-thioester-dependent enzymes. Shared homology indicates that the beta-acetal ester-dependent acyltransferases are derived from a common hydrolytic ancestor of the Serine CarboxyPeptidase (SCP) type, giving rise to the name Serine CarboxyPeptidase-Like (SCPL) acyltransferases. We have analyzed structure-function relationships, reaction mechanism and sequence evolution of Arabidopsis 1-O-sinapoyl-beta-glucose:L-malate sinapoyltransferase (AtSMT) and related enzymes to investigate molecular changes required to impart acyltransferase activity to hydrolytic enzymes. AtSMT has maintained the catalytic triad of the hydrolytic ancestor as well as part of the H-bond network for substrate recognition to bind the acyl acceptor L-malate. A Glu/Asp substitution at the amino acid position preceding the catalytic Ser supports binding of the acyl donor 1-O-sinapoyl-beta-glucose and was found highly conserved among SCPL acyltransferases. The AtSMT-catalyzed acyl transfer reaction follows a random sequential bi-bi mechanism that requires both substrates 1-O-sinapoyl-beta-glucose and L-malate bound in an enzyme donor-acceptor complex to initiate acyl transfer. Together with the strong fixation of the acyl acceptor L-malate, the acquisition of this reaction mechanism favours transacylation over hydrolysis in AtSMT catalysis. The model structure and enzymatic side activities reveal that the AtSMT-mediated acyl transfer proceeds via a short-lived acyl enzyme complex. With regard to evolution, the SCPL acyltransferase clade most likely represents a recent development. The encoding genes are organized in a tandem-arranged cluster with partly overlapping functions. With other enzymes encoded by the respective gene cluster on Arabidopsis chromosome 2, AtSMT shares the enzymatic side activity to disproportionate 1-O-sinapoyl-beta-glucoses to produce 1,2-di-O-sinapoyl-beta-glucose. In the absence of the acyl acceptor L-malate, a residual esterase activity became obvious as a remnant of the hydrolytic ancestor. With regard to the evolution of Arabidopsis SCPL acyltransferases, our results suggest early neofunctionalization of the hydrolytic ancestor toward acyltransferase activity and acyl donor specificity for 1-O-sinapoyl-beta-glucose followed by subfunctionalization to recognize different acyl acceptors.
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Affiliation(s)
- Felix Stehle
- Department of Secondary Metabolism, Leibniz Institute of Plant Biochemistry (IPB), Halle (Saale), Germany
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16
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Park SY, Lee SH, Lee J, Nishi K, Kim YS, Jung CH, Kim JS. High-resolution structure of ybfF from Escherichia coli K12: a unique substrate-binding crevice generated by domain arrangement. J Mol Biol 2008; 376:1426-37. [PMID: 18215690 DOI: 10.1016/j.jmb.2007.12.062] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2007] [Revised: 12/08/2007] [Accepted: 12/23/2007] [Indexed: 11/30/2022]
Abstract
Esterases are one of the most common enzymes and are involved in diverse cellular functions. ybfF protein from Escherichia coli (Ec_ybfF) belongs to the esterase family for the large substrates, palmitoyl coenzyme A and malonyl coenzyme A, which are important cellular intermediates for energy conversion and biomolecular synthesis. To obtain molecular information on ybfF esterase, which is found in a wide range of microorganisms, we elucidated the crystal structures of Ec_ybfF in complexes with small molecules at resolutions of 1.1 and 1.68 A, respectively. The structure of Ec_ybfF is composed of a globular alpha/beta hydrolase domain with a three-helical bundle cap, which is linked by a kinked helix to the alpha/beta hydrolase domain. It contains a catalytic tetrad of Ser-His-Asp-Ser with the first Ser acting as a nucleophile. The unique spatial arrangement and orientation of the helical cap with respect to the alpha/beta hydrolase domain form a substrate-binding crevice for large substrates. The helical cap is also directly involved in catalysis by providing a substrate anchor, viz., the conserved residues of Arg123 and Tyr208. The high-resolution structure of Ec_ybfF shows that the inserted helical bundle structure and its spatial orientation with respect to the alpha/beta hydrolase domain are critical for creating a large inner space and constituting a specific active site, thereby providing the broad substrate spectrum toward large biomolecules.
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Affiliation(s)
- Suk-Youl Park
- Department of Chemistry and Institute of Basic Sciences, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, Korea
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17
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Crystal structure of hyperthermophilic esterase EstE1 and the relationship between its dimerization and thermostability properties. BMC STRUCTURAL BIOLOGY 2007; 7:47. [PMID: 17625021 PMCID: PMC1936996 DOI: 10.1186/1472-6807-7-47] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Accepted: 07/12/2007] [Indexed: 11/28/2022]
Abstract
Background EstE1 is a hyperthermophilic esterase belonging to the hormone-sensitive lipase family and was originally isolated by functional screening of a metagenomic library constructed from a thermal environmental sample. Dimers and oligomers may have been evolutionally selected in thermophiles because intersubunit interactions can confer thermostability on the proteins. The molecular mechanisms of thermostabilization of this extremely thermostable esterase are not well understood due to the lack of structural information. Results Here we report for the first time the 2.1-Å resolution crystal structure of EstE1. The three-dimensional structure of EstE1 exhibits a classic α/β hydrolase fold with a central parallel-stranded beta sheet surrounded by alpha helices on both sides. The residues Ser154, Asp251, and His281 form the catalytic triad motif commonly found in other α/β hydrolases. EstE1 exists as a dimer that is formed by hydrophobic interactions and salt bridges. Circular dichroism spectroscopy and heat inactivation kinetic analysis of EstE1 mutants, which were generated by structure-based site-directed mutagenesis of amino acid residues participating in EstE1 dimerization, revealed that hydrophobic interactions through Val274 and Phe276 on the β8 strand of each monomer play a major role in the dimerization of EstE1. In contrast, the intermolecular salt bridges contribute less significantly to the dimerization and thermostability of EstE1. Conclusion Our results suggest that intermolecular hydrophobic interactions are essential for the hyperthermostability of EstE1. The molecular mechanism that allows EstE1 to endure high temperature will provide guideline for rational design of a thermostable esterase/lipase using the lipolytic enzymes showing structural similarity to EstE1.
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18
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Rhee JK, Kim DY, Ahn DG, Yun JH, Jang SH, Shin HC, Cho HS, Pan JG, Oh JW. Analysis of the thermostability determinants of hyperthermophilic esterase EstE1 based on its predicted three-dimensional structure. Appl Environ Microbiol 2006; 72:3021-5. [PMID: 16598011 PMCID: PMC1449032 DOI: 10.1128/aem.72.4.3021-3025.2006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The three-dimensional (3D) structure of the hyperthermophilic esterase EstE1 was constructed by homology modeling using Archaeoglobus fulgidus esterase as a reference, and the thermostability-structure relationship was analyzed. Our results verified the predicted 3D structure of EstE1 and identified the ion pair networks and hydrophobic interactions that are critical determinants for the thermostability of EstE1.
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Affiliation(s)
- Jin-Kyu Rhee
- Department of Biotechnology, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749, South Korea
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19
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Bai T, Becker M, Gupta A, Strike P, Murphy VJ, Anders RF, Batchelor AH. Structure of AMA1 from Plasmodium falciparum reveals a clustering of polymorphisms that surround a conserved hydrophobic pocket. Proc Natl Acad Sci U S A 2005; 102:12736-41. [PMID: 16129835 PMCID: PMC1200259 DOI: 10.1073/pnas.0501808102] [Citation(s) in RCA: 157] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2005] [Indexed: 12/14/2022] Open
Abstract
Apical membrane antigen 1 (AMA1) is a leading malaria vaccine candidate that possesses polymorphisms that may pose a problem for a vaccine based on this antigen. Knowledge of the distribution of the polymorphic sites on the surface of AMA1 is necessary to obtain a detailed understanding of their significance for vaccine development. For this reason we have sought to determine the three-dimensional structure of AMA1 using x-ray crystallography. The central two-thirds of AMA1 is relatively conserved among Plasmodium species as well as more distantly related apicomplexan parasites, and contains two clusters of disulfide-bonded cysteines termed domains I and II. The crystal structure of this fragment of AMA1 reported here reveals that domains I+II consists of two intimately associated PAN domains. PAN domain I contains many long loops that extend from the domain core and form a scaffold for numerous polymorphic residues. This extreme adaptation of a PAN domain reveals how malaria parasites have introduced significant flexibility and variation into AMA1 to evade protective human antibody responses. The polymorphisms on the AMA1 surface are exclusively located on one side of the molecule, presumably because this region of AMA1 is most accessible to antibodies reacting with the parasite surface. Moreover, the most highly polymorphic residues surround a conserved hydrophobic trough that is ringed by domain I and domain II loops. Precedents set by viral receptor proteins would suggest that this is likely to be the AMA1 receptor binding pocket.
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Affiliation(s)
- Tao Bai
- University of Maryland School of Pharmacy, 20 Penn Street, Baltimore, MD 21201, USA
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20
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Hudáky I, Gáspári Z, Carugo O, Cemazar M, Pongor S, Perczel A. Vicinal disulfide bridge conformers by experimental methods and by ab initio and DFT molecular computations. Proteins 2004; 55:152-68. [PMID: 14997549 DOI: 10.1002/prot.10581] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A systematic comparison is made between experimental and computational data gained on vicinal disulfide bridges in proteins and peptides. Structural and stability data of ab initio and density functional theory (DFT) calculations on the model compound 4,5-ditiaheptano-7-lactam and the model peptide HCO-ox-[Cys-Cys]-NH2 at RHF/3-21G*, B3LYP/6-31+G(d), and B3LYP/6-311++G(d,p) levels of theory are presented. The data on Xxx-Cys-Cys-Yyy type amino acid sequence units retrieved from PDB SELECT, along with data on sequence units that have vicinal disulfide bridge, taken from the Brookhaven Protein Data Bank, are conformationally characterized. Amino acid backbone conformations, cis-trans isomerism of the amide bond between the two cysteine residues, and ring puckering are studied. Ring puckers are characterized by their relation to the conformers of the parent 4,5-ditiaheptano-7-lactam. Computational precision and accuracy are proved by frequency calculation and solvent model optimization on selected conformers. It is found that the ox-[Cys-Cys] unit is able to accept types I, II, VIa, VIb, and VIII beta-turn structures.
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Affiliation(s)
- Ilona Hudáky
- Department of Organic Chemistry, Eötvös Loránd University, Budapest, Hungary
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21
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Giles NM, Watts AB, Giles GI, Fry FH, Littlechild JA, Jacob C. Metal and redox modulation of cysteine protein function. CHEMISTRY & BIOLOGY 2003; 10:677-93. [PMID: 12954327 DOI: 10.1016/s1074-5521(03)00174-1] [Citation(s) in RCA: 321] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In biological systems, the amino acid cysteine combines catalytic activity with an extensive redox chemistry and unique metal binding properties. The interdependency of these three aspects of the thiol group permits the redox regulation of proteins and metal binding, metal control of redox activity, and ligand control of metal-based enzyme catalysis. Cysteine proteins are therefore able to act as "redox switches," to sense concentrations of oxidative stressors and unbound zinc ions in the cytosol, to provide a "storage facility" for excess metal ions, to control the activity of metalloproteins, and to take part in important regulatory and signaling pathways. The diversity of cysteine's multiple roles in vivo is equally as fascinating as it is promising for future biochemical and pharmacological research.
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Affiliation(s)
- Niroshini M Giles
- School of Biological and Chemical Sciences, University of Exeter, Stocker Road, EX4 4QD, Exeter, United Kingdom
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22
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Nitz M, Franz KJ, Maglathlin RL, Imperiali B. A powerful combinatorial screen to identify high-affinity terbium(III)-binding peptides. Chembiochem 2003; 4:272-6. [PMID: 12672106 DOI: 10.1002/cbic.200390047] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Lanthanide-binding tags (LBTs) are protein fusion partners consisting of encoded amino acids that bind lanthanide ions with high affinity. Herein, we present a new screening methodology for the identification of new LBT sequences with high affinity for Tb(3+) ions and intense luminescence properties. This methodology utilizes solid-phase split-and-pool combinatorial peptide synthesis. Orthogonally cleavable linkers allow an efficient two-step screening procedure. The initial screen avoids the interference caused by on-bead screening by photochemically releasing a portion of the peptides into an agarose matrix for evaluation. The secondary screen further characterizes each winning sequence in a defined aqueous solution. Employment of this methodology on a series of focused combinatorial libraries yielded a linear peptide sequence of 17 encoded amino acids that demonstrated a 140-fold increase in affinity (57 nM dissociation constant, K(D)) over previously reported lanthanide-binding peptides. This linear sequence was macrocyclized by introducing a disulfide bond between flanking cysteine residues to produce a peptide with a 2-nM apparent dissociation constant for Tb(3+) ions.Supporting information for this article is available on the WWW under http://www.chemphyschem.org or from the author.
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Affiliation(s)
- Mark Nitz
- Department of Chemistry Massachusetts Institute of Technology Cambridge, MA 02139, USA
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23
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Tyndall JDA, Sinchaikul S, Fothergill-Gilmore LA, Taylor P, Walkinshaw MD. Crystal structure of a thermostable lipase from Bacillus stearothermophilus P1. J Mol Biol 2002; 323:859-69. [PMID: 12417199 DOI: 10.1016/s0022-2836(02)01004-5] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We describe the first lipase structure from a thermophilic organism. It shares less than 20% amino acid sequence identity with other lipases for which there are crystal structures, and shows significant insertions compared with the typical alpha/beta hydrolase canonical fold. The structure contains a zinc-binding site which is unique among all lipases with known structures, and which may play a role in enhancing thermal stability. Zinc binding is mediated by two histidine and two aspartic acid residues. These residues are present in comparable positions in the sequences of certain lipases for which there is as yet no crystal structural information, such as those from Staphylococcal species and Arabidopsis thaliana. The structure of Bacillus stearothermophilus P1 lipase provides a template for other thermostable lipases, and offers insight into mechanisms used to enhance thermal stability which may be of commercial value in engineering lipases for industrial uses.
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Affiliation(s)
- Joel D A Tyndall
- Structural Biochemistry Group, Institute of Cell and Molecular Biology, University of Edinburgh, Michael Swann Building, King's Buildings, Mayfield Road, Scotland, UK
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Edmundson AB. Reminiscences: joyous moments along the road from here to there and back again. J Mol Recognit 2002; 15:227-39. [PMID: 12447899 DOI: 10.1002/jmr.583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Allen B Edmundson
- The Crystallography Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City 73104, USA.
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25
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Reva B, Finkelstein A, Topiol S. Threading with chemostructural restrictions method for predicting fold and functionally significant residues: application to dipeptidylpeptidase IV (DPP-IV). Proteins 2002; 47:180-93. [PMID: 11933065 DOI: 10.1002/prot.10076] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We present a new method for more accurate modeling of protein structure, called threading with chemostructural restrictions. This method addresses those cases in which a target sequence has only remote homologues of known structure for which sequence comparison methods cannot provide accurate alignments. Although remote homologues cannot provide an accurate model for the whole chain, they can be used in constructing practically useful models for the most conserved-and often the most interesting-part of the structure. For many proteins of interest, one can suggest certain chemostructural patterns for the native structure based on the available information on the structural superfamily of the protein, the type of activity, the sequence location of the functionally significant residues, and other factors. We use such patterns to restrict (1) a number of possible templates, and (2) a number of allowed chain conformations on a template. The latter restrictions are imposed in the form of additional template potentials (including terms acting as sequence anchors) that act on certain residues. This approach is tested on remote homologues of alpha/beta-hydrolases that have significant structural similarity in the positions of their catalytic triads. The study shows that, in spite of significant deviations between the model and the native structures, the surroundings of the catalytic triad (positions of C(alpha) atoms of 20-30 nearby residues) can be reproduced with accuracy of 2-3 A. We then apply the approach to predict the structure of dipeptidylpeptidase IV (DPP-IV). Using experimentally available data identifying the catalytic triad residues of DPP-IV (David et al., J Biol Chem 1993;268:17247-17252); we predict a model structure of the catalytic domain of DPP-IV based on the 3D fold of prolyl oligopeptidase (Fulop et al., Cell 1998;94:161-170) and use this structure for modeling the interaction of DPP-IV with inhibitor.
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Affiliation(s)
- Boris Reva
- Novartis Institute for Biomedical Research, Summit, New Jersey, USA.
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Bruner SD, Weber T, Kohli RM, Schwarzer D, Marahiel MA, Walsh CT, Stubbs MT. Structural basis for the cyclization of the lipopeptide antibiotic surfactin by the thioesterase domain SrfTE. Structure 2002; 10:301-10. [PMID: 12005429 DOI: 10.1016/s0969-2126(02)00716-5] [Citation(s) in RCA: 177] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Many biologically active natural peptides are synthesized by nonribosomal peptide synthetases (NRPS). Product release is accomplished by dedicated thioesterase (TE) domains, some of which catalyze an intramolecular cyclization to form macrolactone or macrolactam cyclic peptides. The excised 28 kDa SrfTE domain, a member of the alpha/beta hydrolase enzyme family, exhibits a distinctive bowl-shaped hydrophobic cavity that hosts the acylpeptide substrate and tolerates its folding to form a cyclic structure. A substrate analog confirms the substrate binding site and suggests a mechanism for substrate acylation/deacylation. Docking of the peptidyl carrier protein domain immediately preceding SrfTE positions the 4'-phosphopantheinyl prosthetic group that transfers the nascent acyl-peptide chain to SrfTE. The structure provides a basis for understanding the mechanism of acyl-PCP substrate recognition and for the cyclization reaction that results in release of the macrolactone cyclic heptapeptide.
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Affiliation(s)
- Steven D Bruner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
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