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Chang YJ, Sung JH, Lee CS, Lee JH, Park HH. Comparison of the structure and activity of thioredoxin 2 and thioredoxin 1 from Acinetobacter baumannii. IUCRJ 2023; 10:147-155. [PMID: 36752373 PMCID: PMC9980383 DOI: 10.1107/s2052252523000404] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 01/16/2023] [Indexed: 06/18/2023]
Abstract
Thioredoxin (Trx) is essential in a redox-control system, with many bacteria containing two Trxs: Trx1 and Trx2. Due to a Trx system's critical function, Trxs are targets for novel antibiotics. Here, a 1.20 Å high-resolution structure of Trx2 from Acinetobacter baumannii (abTrx2), an antibiotic resistant pathogenic superbug, is elucidated. By comparing Trx1 and Trx2, it is revealed that the two Trxs possess similar activity, although Trx2 contains an additional N-terminal zinc-finger domain and exhibits more flexible properties in solution. Finally, it is shown that the Trx2 zinc-finger domain might be rotatable and that proper zinc coordination at the zinc-finger domain is critical to abTrx2 activity. This study enhances understanding of the Trx system and will facilitate the design of novel antibiotics.
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Affiliation(s)
- Ye Ji Chang
- College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
- Department of Global Innovative Drugs, Graduate School of Chung-Ang University, Seoul 06974, Republic of Korea
| | - Ji Hye Sung
- College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
- Department of Global Innovative Drugs, Graduate School of Chung-Ang University, Seoul 06974, Republic of Korea
| | - Chang Sup Lee
- College of Pharmacy and Research Institute of Pharmaceutical Science, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Jun Hyuck Lee
- Unit of Research for Practical Application, Korea Polar Research Institute, Incheon 21990, Republic of Korea
- Department of Polar Sciences, University of Science and Technology, Incheon 21990, Republic of Korea
| | - Hyun Ho Park
- College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
- Department of Global Innovative Drugs, Graduate School of Chung-Ang University, Seoul 06974, Republic of Korea
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2
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Chang YJ, Park HH. High-resolution crystal structure of Acinetobacter baumannii thioredoxin 1. Biochem Biophys Res Commun 2022; 608:1-7. [DOI: 10.1016/j.bbrc.2022.03.134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 03/25/2022] [Indexed: 11/02/2022]
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Nguyen TT, Hoang T, Tran KN, Kim H, Jang SH, Lee C. Essential roles of buried phenylalanine in the structural stability of thioredoxin from a psychrophilic Arctic bacterium Sphingomonas sp. PLoS One 2021; 16:e0261123. [PMID: 34910731 PMCID: PMC8673628 DOI: 10.1371/journal.pone.0261123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 11/24/2021] [Indexed: 11/21/2022] Open
Abstract
Thioredoxin (Trx), a small redox protein, exhibits thermal stability at high temperatures regardless of its origin, including psychrophiles. Trxs have a common structure consisting of the central β-sheet flanked by an aliphatic cluster on one side and an aromatic cluster on the other side. Although the roles of aromatic amino acids in the folding and stability of proteins have been studied extensively, the contributions of aromatic residues to the stability and function of Trx, particularly Trxs from cold-adapted organisms, have not been fully elucidated. This study examined the roles of aromatic amino acids in the aromatic cluster of a Trx from the psychrophilic Arctic bacterium Sphingomonas sp. PAMC 26621 (SpTrx). The aromatic cluster of SpTrx was comprised of W11, F26, F69, and F80, in which F26 at the β2 terminus was buried inside. The substitution of tyrosine for F26 changed the SpTrx conformation substantially compared to that of F69 and F80. Further biochemical and spectroscopic investigations on F26 showed that the F26Y, F26W, and F26A mutants resulted in structural instability of SpTrx in both urea- and temperature-induced unfolding and lower insulin reduction activities. The Trx reductase (SpTR) showed lower catalytic efficiencies against F26 mutants compared to the wild-type SpTrx. These results suggest that buried F26 is essential for maintaining the active-site conformation of SpTrx as an oxidoreductase and its structural stability for interactions with SpTR at colder temperatures.
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Affiliation(s)
- Thu-Thuy Nguyen
- Department of Biomedical Science and Center for Bio-Nanomaterials, Daegu University, Gyeongsan, South Korea
| | - Trang Hoang
- Department of Biomedical Science and Center for Bio-Nanomaterials, Daegu University, Gyeongsan, South Korea
| | - Kiet N. Tran
- Department of Biomedical Science and Center for Bio-Nanomaterials, Daegu University, Gyeongsan, South Korea
| | - Hyeonji Kim
- Department of Biomedical Science and Center for Bio-Nanomaterials, Daegu University, Gyeongsan, South Korea
| | - Sei-Heon Jang
- Department of Biomedical Science and Center for Bio-Nanomaterials, Daegu University, Gyeongsan, South Korea
| | - ChangWoo Lee
- Department of Biomedical Science and Center for Bio-Nanomaterials, Daegu University, Gyeongsan, South Korea
- * E-mail:
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Bravo-Chaucanés CP, Abadio AKR, Kioshima ÉS, Felipe MSS, Barbosa JARG. Crystal structure of thioredoxin 1 from Cryptococcus neoformans at 1.8 Å resolution shows unexpected plasticity of the loop preceding the catalytic site. Biochem Biophys Rep 2020; 21:100724. [PMID: 32021910 PMCID: PMC6994535 DOI: 10.1016/j.bbrep.2019.100724] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 11/19/2019] [Accepted: 12/28/2019] [Indexed: 11/26/2022] Open
Abstract
An elevated prevalence of cryptococcal infection is a tendency in low-income countries and constitutes a global public health problem due to factors such as the limited efficacy of antifungal therapy and the AIDS/transplant immunocompromised patients. The fungus Cryptococcus neoformans, implicated in this burden, has had several genes validated as drug targets. Among them, the thioredoxin system is one of the major regulators of redox homeostasis and antioxidant defense acting on protein disulfide bonds. Thioredoxin 1 from C. neoformans (CnTrx1) was cloned and expressed in E. coli and the recombinant protein was purified and crystallized. Functional assay shows that CnTrx1 catalyzes the reduction of insulin disulfide bonds using dithiothreitol, while acting as a monomer in solution. The crystal structure of oxidized CnTrx1 at 1.80 Å resolution presents a dimer in the asymmetric unit with typical Trx-fold. Differences between the monomers in the asymmetric unit are found specially in the loop leading to the Cys-Gly-Pro-Cys active-site motif, being even larger when compared to those found between reduced and oxidized states of other thioredoxins. Although the thioredoxins have been isolated and characterized from many organisms, this new structural report provides important clues for understanding the binding and specificity of CnTrx1 to its targets.
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Affiliation(s)
- Claudia Patricia Bravo-Chaucanés
- Laboratório de Biofísica Molecular, Departamento de Biologia Celular, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF, Brazil
| | | | | | - Maria Sueli Soares Felipe
- Universidade Católica de Brasília, Pós-Graduação em Ciências Genômicas e Biotecnologia, Brasília, DF, Brazil
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Gat Y, Vardi-Kilshtain A, Grossman I, Major DT, Fass D. Enzyme structure captures four cysteines aligned for disulfide relay. Protein Sci 2014; 23:1102-12. [PMID: 24888638 PMCID: PMC4116658 DOI: 10.1002/pro.2496] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 05/28/2014] [Accepted: 05/28/2014] [Indexed: 11/09/2022]
Abstract
Thioredoxin superfamily proteins introduce disulfide bonds into substrates, catalyze the removal of disulfides, and operate in electron relays. These functions rely on one or more dithiol/disulfide exchange reactions. The flavoenzyme quiescin sulfhydryl oxidase (QSOX), a catalyst of disulfide bond formation with an interdomain electron transfer step in its catalytic cycle, provides a unique opportunity for exploring the structural environment of enzymatic dithiol/disulfide exchange. Wild-type Rattus norvegicus QSOX1 (RnQSOX1) was crystallized in a conformation that juxtaposes the two redox-active di-cysteine motifs in the enzyme, presenting the entire electron-transfer pathway and proton-transfer participants in their native configurations. As such a state cannot generally be enriched and stabilized for analysis, RnQSOX1 gives unprecedented insight into the functional group environments of the four cysteines involved in dithiol/disulfide exchange and provides the framework for analysis of the energetics of electron transfer in the presence of the bound flavin adenine dinucleotide cofactor. Hybrid quantum mechanics/molecular mechanics (QM/MM) free energy simulations based on the X-ray crystal structure suggest that formation of the interdomain disulfide intermediate is highly favorable and secures the flexible enzyme in a state from which further electron transfer via the flavin can occur.
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Affiliation(s)
- Yair Gat
- Department of Structural Biology, Weizmann Institute of ScienceRehovot, 76100, Israel
| | - Alexandra Vardi-Kilshtain
- Department of Chemistry and the Lise Meitner-Minerva Center of Computational Quantum Chemistry, Bar Ilan UniversityRamat Gan, 52900, Israel
| | - Iris Grossman
- Department of Structural Biology, Weizmann Institute of ScienceRehovot, 76100, Israel
| | - Dan Thomas Major
- Department of Chemistry and the Lise Meitner-Minerva Center of Computational Quantum Chemistry, Bar Ilan UniversityRamat Gan, 52900, Israel
| | - Deborah Fass
- Department of Structural Biology, Weizmann Institute of ScienceRehovot, 76100, Israel
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Kaur M, Rob A, Caton-Williams J, Huang Z. Biochemistry of Nucleic Acids Functionalized with Sulfur, Selenium, and Tellurium: Roles of the Single-Atom Substitution. ACTA ACUST UNITED AC 2013. [DOI: 10.1021/bk-2013-1152.ch005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
Affiliation(s)
- Manindar Kaur
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30303
| | - Abdur Rob
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30303
| | | | - Zhen Huang
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30303
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Røhr ÅK, Hammerstad M, Andersson KK. Tuning of thioredoxin redox properties by intramolecular hydrogen bonds. PLoS One 2013; 8:e69411. [PMID: 23936007 PMCID: PMC3720550 DOI: 10.1371/journal.pone.0069411] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 06/07/2013] [Indexed: 01/22/2023] Open
Abstract
Thioredoxin-like proteins contain a characteristic C-x-x-C active site motif and are involved in a large number of biological processes ranging from electron transfer, cellular redox level maintenance, and regulation of cellular processes. The mechanism for deprotonation of the buried C-terminal active site cysteine in thioredoxin, necessary for dissociation of the mixed-disulfide intermediate that occurs under thiol/disulfide mediated electron transfer, is not well understood for all thioredoxin superfamily members. Here we have characterized a 8.7 kD thioredoxin (BC3987) from Bacillus cereus that unlike the typical thioredoxin appears to use the conserved Thr8 side chain near the unusual C-P-P-C active site to increase enzymatic activity by forming a hydrogen bond to the buried cysteine. Our hypothesis is based on biochemical assays and thiolate pKa titrations where the wild type and T8A mutant are compared, phylogenetic analysis of related thioredoxins, and QM/MM calculations with the BC3987 crystal structure as a precursor for modeling of reduced active sites. We suggest that our model applies to other thioredoxin subclasses with similar active site arrangements.
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Mullins EA, Starks CM, Francois JA, Sael L, Kihara D, Kappock TJ. Formyl-coenzyme A (CoA):oxalate CoA-transferase from the acidophile Acetobacter aceti has a distinctive electrostatic surface and inherent acid stability. Protein Sci 2012; 21:686-96. [PMID: 22374910 DOI: 10.1002/pro.2054] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 01/26/2012] [Accepted: 02/20/2012] [Indexed: 11/09/2022]
Abstract
Bacterial formyl-CoA:oxalate CoA-transferase (FCOCT) and oxalyl-CoA decarboxylase work in tandem to perform a proton-consuming decarboxylation that has been suggested to have a role in generalized acid resistance. FCOCT is the product of uctB in the acidophilic acetic acid bacterium Acetobacter aceti. As expected for an acid-resistance factor, UctB remains folded at the low pH values encountered in the A. aceti cytoplasm. A comparison of crystal structures of FCOCTs and related proteins revealed few features in UctB that would distinguish it from nonacidophilic proteins and thereby account for its acid stability properties, other than a strikingly featureless electrostatic surface. The apparently neutral surface is a result of a "speckled" charge decoration, in which charged surface residues are surrounded by compensating charges but do not form salt bridges. A quantitative comparison among orthologs identified a pattern of residue substitution in UctB that may be a consequence of selection for protein stability by constant exposure to acetic acid. We suggest that this surface charge pattern, which is a distinctive feature of A. aceti proteins, creates a stabilizing electrostatic network without stiffening the protein or compromising protein-solvent interactions.
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Affiliation(s)
- Elwood A Mullins
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907, USA
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Perez-Jimenez R, Inglés-Prieto A, Zhao ZM, Sanchez-Romero I, Alegre-Cebollada J, Kosuri P, Garcia-Manyes S, Kappock TJ, Tanokura M, Holmgren A, Sanchez-Ruiz JM, Gaucher EA, Fernandez JM. Single-molecule paleoenzymology probes the chemistry of resurrected enzymes. Nat Struct Mol Biol 2011; 18:592-6. [PMID: 21460845 PMCID: PMC3087858 DOI: 10.1038/nsmb.2020] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Accepted: 01/24/2011] [Indexed: 01/01/2023]
Abstract
A journey back in time is possible at the molecular level by reconstructing proteins from extinct organisms. Here we report the reconstruction, based on sequence predicted by phylogenetic analysis, of seven Precambrian thioredoxin enzymes (Trx), dating back between ~1.4 and ~4 billion years (Gyr). The reconstructed enzymes are up to 32° C more stable than modern enzymes and the oldest show significantly higher activity than extant ones at pH 5. We probed their mechanisms of reduction using single-molecule force spectroscopy. From the force-dependency of the rate of reduction of an engineered substrate, we conclude that ancient Trxs utilize chemical mechanisms of reduction similar to those of modern enzymes. While Trx enzymes have maintained their reductase chemistry unchanged, they have adapted over a 4 Gyr time span to the changes in temperature and ocean acidity that characterize the evolution of the global environment from ancient to modern Earth.
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Affiliation(s)
- Raul Perez-Jimenez
- Department of Biological Sciences, Columbia University, New York, New York, USA.
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Caton-Williams J, Huang Z. Biochemistry of selenium-derivatized naturally occurring and unnatural nucleic acids. Chem Biodivers 2008; 5:396-407. [PMID: 18357549 DOI: 10.1002/cbdv.200890040] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Selenium (Se) can provide unique biochemical and biological functions, and properties to macromolecules, including protein and RNA. Although Se has not yet been found in DNA, identification of the presence of Se in natural tRNAs has led to discovery of the naturally occurring 2-selenouridine and 5-[(methylamino)methyl]-2-selenouridine (mnm(5)se(2)U). The Se-atoms at C(2) of the modified uridines are introduced by 2-selenouridine synthase via displacement of the S-atoms in the corresponding 2-thiouridine nucleotides of the tRNAs, and selenophosphate is used as the Se donor. The research indicated that mnm(5)se(2)U is located at the first or wobble position of the anticodons in several bacterial tRNAs, including tRNA(Lys), tRNA(Glu), and tRNA(Gln). The 2-seleno functionality on this modified nucleotide probably improves the translation accuracy and/or efficiency. These observations in vivo suggest that the presence of Se can provide natural RNAs with useful properties to better function and survival. To further investigate the biochemical and structural properties of Se-derivatized nucleic acids (SeNA), we have pioneered chemical and enzymatic synthesis of Se-derivatized nucleic acids, and introduced Se into both RNA and DNA at a variety of positions by atom-specific replacement of oxygen. This review outlines the recent advancements in chemical and biochemical syntheses, and studies of SeNAs, and their potential applications in structural and functional investigation of nucleic acids and their protein complexes.
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