1
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Panda S, Rout M, Mishra S, Turuk J, Pati S, Dehury B. Molecular docking and MD simulations reveal protease inhibitors block the catalytic residues in Prp8 intein of Aspergillus fumigatus: a potential target for antimycotics. J Biomol Struct Dyn 2023:1-16. [PMID: 38149850 DOI: 10.1080/07391102.2023.2298735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 12/18/2023] [Indexed: 12/28/2023]
Abstract
Resistance to azoles and amphotericin B especially in Aspergillus fumigatus is a growing concern towards the treatment of invasive fungal infection. At this critical juncture, intein splicing would be a productive, and innovative target to establish therapies against resistant strains. Intein splicing is the central event for the activation of host protein, essential for the growth and survival of various microorganisms including A. fumigatus. The splicing process is a four-step protease-like nucleophilic cascade. Thus, we hypothesise that protease inhibitors would successfully halt intein splicing and potentially restrict the growth of the aforementioned pathogen. Using Rosetta Fold and molecular dynamics simulations, we modelled Prp8 intein structure; resembling classic intein fold with horse shoe shaped splicing domain. To fully comprehend the active site of Afu Prp8 intein, C1, T62, H65, H818, N819 from intein sequences and S820, the first C-extein residue are selected. Molecular docking shows that two FDA-approved drugs, i.e. Lufotrelvir and Remdesivir triphosphate efficiently interact with Prp8 intein from the assortment of 212 protease inhibitors. MD simulation portrayed that Prp8 undergoes conformational change upon ligand binding, and inferred the molecular recognition and stability of the docked complexes. Per-residue decomposition analysis confirms the importance of F: block R802, V803, and Q807 binding pocket in intein splicing domain towards recognition of inhibitors, along with active site residues through strong hydrogen bonds and hydrophobic contacts. However, in vitro and in vivo assays are required to confirm the inhibitory action on Prp8 intein splicing; which may pave the way for the development of new antifungals for A. fumigatus.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Sunita Panda
- Mycology Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Madhusmita Rout
- Bioinformatics Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Sarbani Mishra
- Bioinformatics Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Jyotirmayee Turuk
- Mycology Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Sanghamitra Pati
- Mycology Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Budheswar Dehury
- Bioinformatics Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
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2
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Karasev MM, Verkhusha VV, Shcherbakova DM. Near-Infrared Optogenetic Module for Conditional Protein Splicing. J Mol Biol 2023; 435:168360. [PMID: 37949312 PMCID: PMC10842711 DOI: 10.1016/j.jmb.2023.168360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 10/29/2023] [Accepted: 11/03/2023] [Indexed: 11/12/2023]
Abstract
Optogenetics has emerged as a powerful tool for spatiotemporal control of biological processes. Near-infrared (NIR) light, with its low phototoxicity and deep tissue penetration, holds particular promise. However, the optogenetic control of polypeptide bond formation has not yet been developed. In this study, we introduce a NIR optogenetic module for conditional protein splicing (CPS) based on the gp41-1 intein. We optimized the module to minimize background signals in the darkness and to maximize the contrast between light and dark conditions. Next, we engineered a NIR CPS gene expression system based on the protein ligation of a transcription factor. We applied the NIR CPS for light-triggered protein cleavage to activate gasdermin D, a pore-forming protein that induces pyroptotic cell death. Our NIR CPS optogenetic module represents a promising tool for controlling molecular processes through covalent protein linkage and cleavage.
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Affiliation(s)
- Maksim M Karasev
- Medicum, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland
| | - Vladislav V Verkhusha
- Medicum, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland; Department of Genetics, and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Daria M Shcherbakova
- Department of Genetics, and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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3
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Wood DW, Belfort M, Lennon CW. Inteins-mechanism of protein splicing, emerging regulatory roles, and applications in protein engineering. Front Microbiol 2023; 14:1305848. [PMID: 38029209 PMCID: PMC10663303 DOI: 10.3389/fmicb.2023.1305848] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Protein splicing is a posttranslational process in which an intein segment excises itself from two flanking peptides, referred to as exteins. In the native context, protein splicing results in two separate protein products coupled to the activation of the intein-containing host protein. Inteins are generally described as either full-length inteins, mini-inteins or split inteins, which are differentiated by their genetic structure and features. Inteins can also be divided into three classes based on their splicing mechanisms, which differ in the location of conserved residues that mediate the splicing pathway. Although inteins were once thought to be selfish genetic elements, recent evidence suggests that inteins may confer a genetic advantage to their host cells through posttranslational regulation of their host proteins. Finally, the ability of modified inteins to splice and cleave their fused exteins has enabled many new applications in protein science and synthetic biology. In this review, we briefly cover the mechanisms of protein splicing, evidence for some inteins as environmental sensors, and intein-based applications in protein engineering.
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Affiliation(s)
- David W. Wood
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH, United States
| | - Marlene Belfort
- Department of Biological Sciences and RNA Institute, University at Albany, Albany, NY, United States
| | - Christopher W. Lennon
- Department of Biological Sciences, Murray State University, Murray, KY, United States
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4
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Ariagno TM, Smetana JS, Lennon CW. An artificially split class 3 intein. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000977. [PMID: 37811346 PMCID: PMC10559147 DOI: 10.17912/micropub.biology.000977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 09/20/2023] [Accepted: 09/20/2023] [Indexed: 10/10/2023]
Abstract
Inteins excise themselves from precursor polypeptides through protein splicing, joining N- and C-exteins with a peptide bond. Split inteins are expressed as separate polypeptides that undergo protein trans splicing (PTS). Here, we demonstrate PTS can be achieved using an artificially split class 3 intein. Because class 3 inteins use an internal initiating nucleophile near the C-extein junction, rather than the first residue of the intein, both catalytic nucleophiles are present on a single polypeptide. This results in a compact arrangement of catalytic nucleophiles for PTS compared to the standard arrangement for split class 1 inteins.
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Affiliation(s)
- Tia M. Ariagno
- Department of Biological Sciences, Murray State University, Murray, Kentucky, United States
| | - John S. Smetana
- Department of Biological Sciences, Murray State University, Murray, Kentucky, United States
| | - Christopher W. Lennon
- Department of Biological Sciences, Murray State University, Murray, Kentucky, United States
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5
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Zhan Q, Shi C, Jiang Y, Gao X, Lin Y. Efficient splicing of the CPE intein derived from directed evolution of the Cryptococcus neoformans PRP8 intein. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1310-1318. [PMID: 37489009 PMCID: PMC10448054 DOI: 10.3724/abbs.2023135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/19/2023] [Indexed: 07/26/2023] Open
Abstract
Intein-mediated protein splicing has been widely used in protein engineering; however, the splicing efficiency and extein specificity usually limit its further application. Thus, there is a demand for more general inteins that can overcome these limitations. Here, we study the trans-splicing of CPE intein obtained from the directed evolution of Cne PRP8, which shows that its splicing rate is ~29- fold higher than that of the wild-type. When the +1 residue of C-extein is changed to cysteine, CPE also shows high splicing activity. Faster association and higher affinity may contribute to the high splicing rate compared with wild-type intein. These findings have important implications for the future engineering of inteins and provide clues for fundamental studies of protein structure and folding.
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Affiliation(s)
- Qin Zhan
- College of Biological Science and Medical EngineeringDonghua UniversityShanghai201620China
| | - Changhua Shi
- College of Biological Science and Medical EngineeringDonghua UniversityShanghai201620China
| | - Yu Jiang
- College of Biological Science and Medical EngineeringDonghua UniversityShanghai201620China
| | - Xianling Gao
- Shandong Guoli Biotechnology Co.Ltd.Jinan250101China
| | - Ying Lin
- College of Biological Science and Medical EngineeringDonghua UniversityShanghai201620China
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6
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Boral S, Sen S, Kushwaha T, Inampudi KK, De S. Extein residues regulate the catalytic function of Spl DnaX intein enzyme by restricting the near-attack conformations of the active-site residues. Protein Sci 2023; 32:e4699. [PMID: 37313648 PMCID: PMC10288555 DOI: 10.1002/pro.4699] [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: 03/23/2023] [Revised: 05/30/2023] [Accepted: 06/06/2023] [Indexed: 06/15/2023]
Abstract
Intein enzymes catalyze the splicing of their flanking polypeptide chains and have found tremendous biotechnological applications. Their terminal residues form the catalytic core and participate in the splicing reaction. Hence, the neighboring N- and C-terminal extein residues influence the catalytic rate. As these extein residues vary depending on the substrate identity, we tested the influence of 20 amino acids at these sites in the Spl DnaX intein and observed significant variation of spliced product as well as N- and C-terminus cleavage product formation. We investigated the dependence of these reactions on the extein residues by molecular dynamics (MD) simulations on eight extein variants, and found that the conformational sampling of the active-site residues of the intein enzyme differed among these extein variants. We found that the extein variants that sample higher population of near-attack conformers (NACs) of the active-site residues undergo higher product formation in our activity assays. Ground state conformers that closely resemble the transition state are referred to as NACs. Very good correlation was observed between the NAC populations from the MD simulations of eight extein variants and the corresponding product formation from our activity assays. Furthermore, this molecular detail enabled us to elucidate the mechanistic roles of several conserved active-site residues in the splicing reaction. Overall, this study shows that the catalytic power of Spl DnaX intein enzyme, and most likely other inteins, depends on the efficiency of formation of NACs in the ground state, which is further modulated by the extein residues.
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Affiliation(s)
- Soumendu Boral
- School of BioscienceIndian Institute of Technology KharagpurKharagpurIndia
| | - Srijon Sen
- School of BioscienceIndian Institute of Technology KharagpurKharagpurIndia
| | - Tushar Kushwaha
- Department of BiophysicsAll India Institute of Medical SciencesNew DelhiIndia
| | - Krishna K. Inampudi
- Department of BiophysicsAll India Institute of Medical SciencesNew DelhiIndia
| | - Soumya De
- School of BioscienceIndian Institute of Technology KharagpurKharagpurIndia
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7
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Abstract
The ability to manipulate the chemical composition of proteins and peptides has been central to the development of improved polypeptide-based therapeutics and has enabled researchers to address fundamental biological questions that would otherwise be out of reach. Protein ligation, in which two or more polypeptides are covalently linked, is a powerful strategy for generating semisynthetic products and for controlling polypeptide topology. However, specialized tools are required to efficiently forge a peptide bond in a chemoselective manner with fast kinetics and high yield. Fortunately, nature has addressed this challenge by evolving enzymatic mechanisms that can join polypeptides using a diverse set of chemical reactions. Here, we summarize how such nature-inspired protein ligation strategies have been repurposed as chemical biology tools that afford enhanced control over polypeptide composition.
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Affiliation(s)
- Rasmus Pihl
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Qingfei Zheng
- Department of Radiation Oncology, College of Medicine, The Ohio State University, Columbus, OH, USA.
- Center for Cancer Metabolism, James Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA.
- Department of Biological Chemistry and Pharmacology, College of Medicine, The Ohio State University, Columbus, OH, USA.
| | - Yael David
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA.
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA.
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8
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YcaO-mediated ATP-dependent peptidase activity in ribosomal peptide biosynthesis. Nat Chem Biol 2023; 19:111-119. [PMID: 36280794 DOI: 10.1038/s41589-022-01141-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 08/11/2022] [Indexed: 12/31/2022]
Abstract
YcaO enzymes catalyze ATP-dependent post-translation modifications on peptides, including the installation of (ox/thi)azoline, thioamide and/or amidine moieties. Here we demonstrate that, in the biosynthesis of the bis-methyloxazolic alkaloid muscoride A, the YcaO enzyme MusD carries out both ATP-dependent cyclodehydration and peptide bond cleavage, which is a mechanism unprecedented for such a reaction. YcaO-catalyzed modifications are proposed to occur through a backbone O-phosphorylated intermediate, but this mechanism remains speculative. We report, to our knowedge, the first characterization of an acyl-phosphate species consistent with the proposed mechanism for backbone amide activation. The 3.1-Å-resolution cryogenic electron microscopy structure of MusD along with biochemical analysis allow identification of residues that enable peptide cleavage reaction. Bioinformatics analysis identifies other cyanobactin pathways that may deploy bifunctional YcaO enzymes. Our structural, mutational and mechanistic studies expand the scope of modifications catalyzed by YcaO proteins to include peptide hydrolysis and provide evidence for a unifying mechanism for the catalytically diverse outcomes.
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9
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Tharappel AM, Li Z, Zhu YC, Wu X, Chaturvedi S, Zhang QY, Li H. Calcimycin Inhibits Cryptococcus neoformans In Vitro and In Vivo by Targeting the Prp8 Intein Splicing. ACS Infect Dis 2022; 8:1851-1868. [PMID: 35948057 PMCID: PMC9464717 DOI: 10.1021/acsinfecdis.2c00137] [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] [Indexed: 01/29/2023]
Abstract
Drug resistance is a significant concern in the treatment of diseases, including cryptococcosis caused by Cryptococcus neoformans (Cne) and Cryptococcus gattii (Cga). Alternative drug targets are necessary to overcome drug resistance before it attains a critical stage. Splicing of inteins from pro-protein precursors is crucial for activities of essential proteins hosting intein elements in many organisms, including human pathogens such as Cne and Cga. Through a high-throughput screening, we identified calcimycin (CMN) as a potent Prp8 intein splicing inhibitor with a minimum inhibitory concentration (MIC) of 1.5 μg/mL against the wild-type Cne-H99 (Cne-WT or Cne). In contrast, CMN inhibited the intein-less mutant strain (Cne-Mut) with a 16-fold higher MIC. Interestingly, Aspergillus fumigatus and a few Candida species were resistant to CMN. Further studies indicated that CMN reduced virulence factors such as urease activity, melanin production, and biofilm formation in Cne. CMN also inhibited Cne intracellular infection in macrophages. In a target-specific split nanoluciferase assay, the IC50 of CMN was 4.6 μg/mL. Binding of CMN to recombinant Prp8 intein was demonstrated by thermal shift assay and microscale thermophoresis. Treating Cne cells with CMN reduced intein splicing. CMN was fungistatic and showed a synergistic effect with the known antifungal drug amphotericin B. Finally, CMN treatment at 20 mg/kg body weight led to 60% reduction in lung fungal load in a cryptococcal pulmonary infection mouse model. Overall, CMN represents a potent antifungal with a novel mechanism of action to treat Cne and possibly Cga infections.
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Affiliation(s)
- Anil Mathew Tharappel
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson Arizona 85721-0207, United States
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
| | - Zhong Li
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson Arizona 85721-0207, United States
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
| | - Yan Chun Zhu
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
| | - Xiangmeng Wu
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson Arizona 85721-0207, United States
| | - Sudha Chaturvedi
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
| | - Qing-Yu Zhang
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson Arizona 85721-0207, United States
| | - Hongmin Li
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson Arizona 85721-0207, United States
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
- The BIO5 Institute, The University of Arizona, Tucson, Arizona 85721, United States
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10
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Prabhala SV, Gierach I, Wood DW. The Evolution of Intein-Based Affinity Methods as Reflected in 30 years of Patent History. Front Mol Biosci 2022; 9:857566. [PMID: 35463948 PMCID: PMC9033041 DOI: 10.3389/fmolb.2022.857566] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/04/2022] [Indexed: 11/18/2022] Open
Abstract
Self-cleaving affinity tags, based on engineered intein protein domains, have been touted as a universal single step purification platform for tagless non-mAb proteins. These approaches provide all of the power and flexibility of tag-based affinity methods, but deliver a tagless target protein suitable for clinical applications without complex process development. This combination of features might accelerate and de-risk biopharmaceutical development by bridging early discovery to full-scale manufacturing under a single platform. Despite this profound promise, intein-based technologies have yet to reach their full potential. This review examines the evolution of intein-based purification methods in the light of several significant intein patents filed over the last 3 decades. Illustrated with actual key figures from each of the relevant patents, key advances are described with a focus on applications in basic research and biopharmaceutical production. Suggestions for extending intein-based purification systems to emerging therapies and non-protein applications are presented as concluding remarks.
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Affiliation(s)
- Sai Vivek Prabhala
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH, United States
| | | | - David W. Wood
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH, United States,Protein Capture Science, Columbus, OH, United States,*Correspondence: David W. Wood,
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11
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SufB intein splicing in Mycobacterium tuberculosis is influenced by two remote conserved N-extein histidines. Biosci Rep 2022; 42:230724. [PMID: 35234249 PMCID: PMC8891592 DOI: 10.1042/bsr20212207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 01/11/2022] [Accepted: 01/27/2022] [Indexed: 11/24/2022] Open
Abstract
Inteins are auto-processing domains that implement a multistep biochemical reaction termed protein splicing, marked by cleavage and formation of peptide bonds. They excise from a precursor protein, generating a functional protein via covalent bonding of flanking exteins. We report the kinetic study of splicing and cleavage reaction in [Fe–S] cluster assembly protein SufB from Mycobacterium tuberculosis (Mtu). Although it follows a canonical intein splicing pathway, distinct features are added by extein residues present in the active site. Sequence analysis identified two conserved histidines in the N-extein region; His-5 and His-38. Kinetic analyses of His-5Ala and His-38Ala SufB mutants exhibited significant reductions in splicing and cleavage rates relative to the SufB wildtype (WT) precursor protein. Structural analysis and molecular dynamics (MD) simulations suggested that Mtu SufB displays a unique mechanism where two remote histidines work concurrently to facilitate N-terminal cleavage reaction. His-38 is stabilized by the solvent-exposed His-5, and can impact N–S acyl shift by direct interaction with the catalytic Cys1. Development of inteins as biotechnological tools or as pathogen-specific novel antimicrobial targets requires a more complete understanding of such unexpected roles of conserved extein residues in protein splicing.
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12
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Beyer HM, Iwaï H. Structural Basis for the Propagation of Homing Endonuclease-Associated Inteins. Front Mol Biosci 2022; 9:855511. [PMID: 35372505 PMCID: PMC8966425 DOI: 10.3389/fmolb.2022.855511] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 02/08/2022] [Indexed: 11/13/2022] Open
Abstract
Inteins catalyze their removal from a host protein through protein splicing. Inteins that contain an additional site-specific endonuclease domain display genetic mobility via a process termed “homing” and thereby act as selfish DNA elements. We elucidated the crystal structures of two archaeal inteins associated with an active or inactive homing endonuclease domain. This analysis illustrated structural diversity in the accessory domains (ACDs) associated with the homing endonuclease domain. To augment homing endonucleases with highly specific DNA cleaving activity using the intein scaffold, we engineered the ACDs and characterized their homing site recognition. Protein engineering of the ACDs in the inteins illuminated a possible strategy for how inteins could avoid their extinction but spread via the acquisition of a diverse accessory domain.
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Affiliation(s)
- Hannes M. Beyer
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
- Institute of Synthetic Biology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Hideo Iwaï
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
- *Correspondence: Hideo Iwaï, or,
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13
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Nanda A, Nasker SS, Kushwaha AK, Ojha DK, Dearden AK, Nayak SK, Nayak S. Gold Nanoparticles Augment N-Terminal Cleavage and Splicing Reactions in Mycobacterium tuberculosis SufB. Front Bioeng Biotechnol 2021; 9:773303. [PMID: 35004641 PMCID: PMC8735848 DOI: 10.3389/fbioe.2021.773303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 11/12/2021] [Indexed: 11/13/2022] Open
Abstract
Protein splicing is a self-catalyzed event where the intervening sequence intein cleaves off, joining the flanking exteins together to generate a functional protein. Attempts have been made to regulate the splicing rate through variations in temperature, pH, and metals. Although metal-regulated protein splicing has been more captivating to researchers, metals were shown to only inhibit splicing reactions that confine their application. This is the first study to show the effect of nanoparticles (NPs) on protein splicing. We found that gold nanoparticles (AuNPs) of various sizes can increase the splicing efficiency by more than 50% and the N-terminal cleavage efficiency by more than 45% in Mycobacterium tuberculosis SufB precursor protein. This study provides an effective strategy for engineering splicing-enhanced intein platforms. UV-vis absorption spectroscopy, isothermal titration calorimetry (ITC), and transmission electron microscopy (TEM) confirmed AuNP interaction with the native protein. Quantum mechanics/molecular mechanics (QM/MM) analysis suggested a significant reduction in the energy barrier at the N-terminal cleavage site in the presence of gold atom, strengthening our experimental evidence on heightened the N-terminal cleavage reaction. The encouraging observation of enhanced N-terminal cleavage and splicing reaction can have potential implementations from developing a rapid drug delivery system to designing a contemporary protein purification system.
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Affiliation(s)
- Ananya Nanda
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, India
| | - Sourya Subhra Nasker
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, India
| | - Anoop K. Kushwaha
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar, India
| | - Deepak Kumar Ojha
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, India
| | - Albert K. Dearden
- Departments of Physics and Astronomy, College of Arts and Sciences, University of South Carolina, Columbia, SC, United States
| | - Saroj K. Nayak
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar, India
| | - Sasmita Nayak
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, India
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14
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Choi H, Eom S, Kim HU, Bae Y, Jung HS, Kang S. Load and Display: Engineering Encapsulin as a Modular Nanoplatform for Protein-Cargo Encapsulation and Protein-Ligand Decoration Using Split Intein and SpyTag/SpyCatcher. Biomacromolecules 2021; 22:3028-3039. [PMID: 34142815 DOI: 10.1021/acs.biomac.1c00481] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Protein cage nanoparticles have a unique spherical hollow structure that provides a modifiable interior space and an exterior surface. For full application, it is desirable to utilize both the interior space and the exterior surface simultaneously with two different functionalities in a well-combined way. Here, we genetically engineered encapsulin protein cage nanoparticles (Encap) as modular nanoplatforms by introducing a split-C-intein (IntC) fragment and SpyTag into the interior and exterior surfaces, respectively. A complementary split-N-intein (IntN) was fused to various protein cargoes, such as NanoLuc luciferase (Nluc), enhanced green fluorescent protein (eGFP), and Nluc-miniSOG, individually, which led to their successful encapsulation into Encaps to form Cargo@Encap through split intein-mediated protein ligation during protein coexpression and cage assembly in bacteria. Conversely, the SpyCatcher protein was fused to various protein ligands, such as a glutathione binder (GST-SC), dimerizing ligands (FKBP12-SC and FRB-SC), and a cancer-targeting affibody (SC-EGFRAfb); subsequently, they were displayed on Cargo@Encaps through SpyTag/SpyCatcher ligation to form Cargo@Encap/Ligands in a mix-and-match manner. Nluc@Encap/glutathione-S-transferase (GST) was effectively immobilized on glutathione (GSH)-coated solid supports exhibiting repetitive and long-term usage of the encapsulated luciferases. We also established luciferase-embedded layer-by-layer (LbL) nanostructures by alternately depositing Nluc@Encap/FKBP12 and Nluc@Encap/FRB in the presence of rapamycin and applied enhanced green fluorescent protein (eGFP)@Encap/EGFRAfb as a target-specific fluorescent imaging probe to visualize specific cancer cells selectively. Modular functionalization of the interior space and the exterior surface of a protein cage nanoparticle may offer the opportunity to develop new protein-based nanostructured devices and nanomedical tools.
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Affiliation(s)
- Hyukjun Choi
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
| | - Soomin Eom
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
| | - Han-Ul Kim
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, 1, Kangwondaehak-gil, Chuncheon-si 24341, Gangwon-do, Korea
| | - Yoonji Bae
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
| | - Hyun Suk Jung
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, 1, Kangwondaehak-gil, Chuncheon-si 24341, Gangwon-do, Korea
| | - Sebyung Kang
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
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15
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Williams JE, Jaramillo MV, Li Z, Zhao J, Wang C, Li H, Mills KV. An alternative domain-swapped structure of the Pyrococcus horikoshii PolII mini-intein. Sci Rep 2021; 11:11680. [PMID: 34083592 PMCID: PMC8175363 DOI: 10.1038/s41598-021-91090-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 05/19/2021] [Indexed: 01/09/2023] Open
Abstract
Protein splicing is a post-translational process by which an intein catalyzes its own excision from flanking polypeptides, or exteins, concomitant with extein ligation. Many inteins have nested homing endonuclease domains that facilitate their propagation into intein-less alleles, whereas other inteins lack the homing endonuclease (HEN) and are called mini-inteins. The mini-intein that interrupts the DNA PolII of Pyrococcus horikoshii has a linker region in place of the HEN domain that is shorter than the linker in a closely related intein from Pyrococcus abyssi. The P. horikoshii PolII intein requires a higher temperature for catalytic activity and is more stable to digestion by the thermostable protease thermolysin, suggesting that it is more rigid than the P. abyssi intein. We solved a crystal structure of the intein precursor that revealed a domain-swapped dimer. Inteins found as domain swapped dimers have been shown to promote intein-mediated protein alternative splicing, but the solved P. horikoshii PolII intein structure has an active site unlikely to be catalytically competent.
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Affiliation(s)
- Jennie E Williams
- Department of Chemistry, College of the Holy Cross, 1 College Street, Worcester, MA, USA
| | - Mario V Jaramillo
- Department of Chemistry, College of the Holy Cross, 1 College Street, Worcester, MA, USA
| | - Zhong Li
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, 12208, USA
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ, 85721, USA
| | - Jing Zhao
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
- China Agricultural University, Beijing, China
| | - Chunyu Wang
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Hongmin Li
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, 12208, USA
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ, 85721, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, USA
| | - Kenneth V Mills
- Department of Chemistry, College of the Holy Cross, 1 College Street, Worcester, MA, USA.
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16
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Panda S, Nanda A, Nasker SS, Sen D, Mehra A, Nayak S. Metal effect on intein splicing: A review. Biochimie 2021; 185:53-67. [PMID: 33727137 DOI: 10.1016/j.biochi.2021.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 03/04/2021] [Accepted: 03/06/2021] [Indexed: 02/08/2023]
Abstract
Inteins are intervening polypeptides that interrupt the functional domains of several important proteins across the three domains of life. Inteins excise themselves from the precursor protein, ligating concomitant extein residues in a process called protein splicing. Post-translational auto-removal of inteins remain critical for the generation of active proteins. The perspective of inteins in science is a robust field of research, however fundamental studies centralized upon splicing regulatory mechanism are imperative for addressing more intricate issues. Controlled engineering of intein splicing has many applications; intein inhibition can facilitate novel drug design, while activation of intein splicing is exploited in protein purification. This paper provides a comprehensive review of the past and recent advances in the splicing regulation via metal-intein interaction. We compare the behavior of different metal ions on diverse intein systems. Though metals such as Zn, Cu, Pt, Cd, Co, Ni exhibit intein inhibitory effect heterogeneously on different inteins, divalent metal ions such as Ca and Mg fail to do so. The observed diversity in the metal-intein interaction arises mostly due to intein polymorphism and variations in atomic structure of metals. A mechanistic understanding of intein regulation by metals in native as well as synthetically engineered intein systems may yield potent intein inhibitors via direct or indirect approach.
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Affiliation(s)
- Sunita Panda
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India
| | - Ananya Nanda
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India
| | - Sourya Subhra Nasker
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India
| | - Debjani Sen
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India
| | - Ashwaria Mehra
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India
| | - Sasmita Nayak
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India.
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17
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Sarkar D, Harms H, Galleano I, Sheikh ZP, Pless SA. Ion channel engineering using protein trans-splicing. Methods Enzymol 2021; 654:19-48. [PMID: 34120713 DOI: 10.1016/bs.mie.2021.01.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Conventional site-directed mutagenesis and genetic code expansion approaches have been instrumental in providing detailed functional and pharmacological insight into membrane proteins such as ion channels. Recently, this has increasingly been complemented by semi-synthetic strategies, in which part of the protein is generated synthetically. This means a vast range of chemical modifications, including non-canonical amino acids (ncAA), backbone modifications, chemical handles, fluorescent or spectroscopic labels and any combination of these can be incorporated. Among these approaches, protein trans-splicing (PTS) is particularly promising for protein reconstitution in live cells. It relies on one or more split inteins, which can spontaneously and covalently link flanking peptide or protein sequences. Here, we describe the use of PTS and its variant tandem PTS (tPTS) in semi-synthesis of ion channels in Xenopus laevis oocytes to incorporate ncAAs, post-translational modifications or metabolically stable mimics thereof. This strategy has the potential to expand the type and number of modifications in ion channel research.
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Affiliation(s)
- Debayan Sarkar
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Hendrik Harms
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Iacopo Galleano
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Zeshan Pervez Sheikh
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
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18
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Mafi A, Purohit R, Vielmas E, Lauinger AR, Lam B, Cheng YS, Zhang T, Huang Y, Kim SK, Goddard WA, Ondrus AE. Hedgehog proteins create a dynamic cholesterol interface. PLoS One 2021; 16:e0246814. [PMID: 33630857 PMCID: PMC7906309 DOI: 10.1371/journal.pone.0246814] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 01/26/2021] [Indexed: 12/27/2022] Open
Abstract
During formation of the Hedgehog (Hh) signaling proteins, cooperative activities of the Hedgehog INTein (Hint) fold and Sterol Recognition Region (SRR) couple autoproteolysis to cholesterol ligation. The cholesteroylated Hh morphogens play essential roles in embryogenesis, tissue regeneration, and tumorigenesis. Despite the centrality of cholesterol in Hh function, the full structure of the Hint-SRR ("Hog") domain that attaches cholesterol to the last residue of the active Hh morphogen remains enigmatic. In this work, we combine molecular dynamics simulations, photoaffinity crosslinking, and mutagenesis assays to model cholesterolysis intermediates in the human Sonic Hedgehog (hSHH) protein. Our results provide evidence for a hydrophobic Hint-SRR interface that forms a dynamic, non-covalent cholesterol-Hog complex. Using these models, we suggest a unified mechanism by which Hh proteins can recruit, sequester, and orient cholesterol, and offer a molecular basis for the effects of disease-causing hSHH mutations.
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Affiliation(s)
- Amirhossein Mafi
- Department of Chemistry, Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Rahul Purohit
- Department of Chemistry, Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Erika Vielmas
- Department of Chemistry, Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Alexa R. Lauinger
- Department of Chemistry, Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Brandon Lam
- Department of Chemistry, Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Yu-Shiuan Cheng
- Department of Chemistry, Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Tianyi Zhang
- Department of Chemistry, Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Yiran Huang
- Department of Chemistry, Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - Soo-Kyung Kim
- Department of Chemistry, Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
| | - William A. Goddard
- Department of Chemistry, Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
- * E-mail: (AEO); (WAG)
| | - Alison E. Ondrus
- Department of Chemistry, Division of Chemistry & Chemical Engineering, California Institute of Technology, Pasadena, California, United States of America
- * E-mail: (AEO); (WAG)
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19
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Abstract
Self-splicing proteins, called inteins, are present in many human pathogens, including the emerging fungal threats Cryptococcus neoformans (Cne) and Cryptococcus gattii (Cga), the causative agents of cryptococcosis. Inhibition of protein splicing in Cryptococcus sp. interferes with activity of the only intein-containing protein, Prp8, an essential intron splicing factor. Here, we screened a small-molecule library to find addititonal, potent inhibitors of the Cne Prp8 intein using a split-GFP splicing assay. This revealed the compound 6G-318S, with IC50 values in the low micromolar range in the split-GFP assay and in a complementary split-luciferase system. A fluoride derivative of the compound 6G-318S displayed improved cytotoxicity in human lung carcinoma cells, although there was a slight reduction in the inhibition of splicing. 6G-318S and its derivative inhibited splicing of the Cne Prp8 intein in vivo in Escherichia coli and in C. neoformans Moreover, the compounds repressed growth of WT C. neoformans and C. gattii In contrast, the inhibitors were less potent at inhibiting growth of the inteinless Candida albicans Drug resistance was observed when the Prp8 intein was overexpressed in C. neoformans, indicating specificity of this molecule toward the target. No off-target activity was observed, such as inhibition of serine/cysteine proteases. The inhibitors bound covalently to the Prp8 intein and binding was reduced when the active-site residue Cys1 was mutated. 6G-318S showed a synergistic effect with amphotericin B and additive to indifferent effects with a few other clinically used antimycotics. Overall, the identification of these small-molecule intein-splicing inhibitors opens up prospects for a new class of antifungals.
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20
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Hoffmann S, Terhorst TME, Singh RK, Kümmel D, Pietrokovski S, Mootz HD. Biochemical and Structural Characterization of an Unusual and Naturally Split Class 3 Intein. Chembiochem 2020; 22:364-373. [PMID: 32813312 PMCID: PMC7891396 DOI: 10.1002/cbic.202000509] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/19/2020] [Indexed: 12/31/2022]
Abstract
Split inteins are indispensable tools for protein engineering because their ligation and cleavage reactions enable unique modifications of the polypeptide backbone. Three different classes of inteins have been identified according to the nature of the covalent intermediates resulting from the acyl rearrangements in the multistep protein‐splicing pathway. Class 3 inteins employ a characteristic internal cysteine for a branched thioester intermediate. A bioinformatic database search of non‐redundant protein sequences revealed the absence of split variants in 1701 class 3 inteins. We have discovered the first reported split class 3 intein in a metagenomics data set and report its biochemical, mechanistic and structural analysis. The AceL NrdHF intein exhibits low sequence conservation with other inteins and marked deviations in residues at conserved key positions, including a variation of the typical class‐3 WCT triplet motif. Nevertheless, functional analysis confirmed the class 3 mechanism of the intein and revealed excellent splicing yields within a few minutes over a wide range of conditions and with barely detectable cleavage side reactions. A high‐resolution crystal structure of the AceL NrdHF precursor and a mutagenesis study explained the importance and roles of several residues at the key positions. Tolerated substitutions in the flanking extein residues and a high affinity between the split intein fragments further underline the intein's future potential as a ligation tool.
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Affiliation(s)
- Simon Hoffmann
- Institute of Biochemistry, University of Muenster, Corrensstraße 36, 48149, Münster, Germany
| | - Tobias M E Terhorst
- Institute of Biochemistry, University of Muenster, Corrensstraße 36, 48149, Münster, Germany
| | - Rohit K Singh
- Institute of Biochemistry, University of Muenster, Corrensstraße 36, 48149, Münster, Germany
| | - Daniel Kümmel
- Institute of Biochemistry, University of Muenster, Corrensstraße 36, 48149, Münster, Germany
| | - Shmuel Pietrokovski
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Henning D Mootz
- Institute of Biochemistry, University of Muenster, Corrensstraße 36, 48149, Münster, Germany
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21
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Woods D, Vangaveti S, Egbanum I, Sweeney AM, Li Z, Bacot-Davis V, LeSassier DS, Stanger M, Hardison GE, Li H, Belfort M, Lennon CW. Conditional DnaB Protein Splicing Is Reversibly Inhibited by Zinc in Mycobacteria. mBio 2020; 11:e01403-20. [PMID: 32665276 PMCID: PMC7360933 DOI: 10.1128/mbio.01403-20] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 06/09/2020] [Indexed: 11/20/2022] Open
Abstract
Inteins, as posttranslational regulatory elements, can tune protein function to environmental changes by conditional protein splicing (CPS). Translated as subdomains interrupting host proteins, inteins splice to scarlessly join flanking sequences (exteins). We used DnaB-intein1 (DnaBi1) from a replicative helicase of Mycobacterium smegmatis to build a kanamycin intein splicing reporter (KISR) that links splicing of DnaBi1 to kanamycin resistance. Using expression in heterologous Escherichia coli, we observed phenotypic classes of various levels of splicing-dependent resistance (SDR) and related these to the insertion position of DnaBi1 within the kanamycin resistance protein (KanR). The KanR-DnaBi1 construct demonstrating the most stringent SDR was used to probe for CPS of DnaB in the native host environment, M. smegmatis We show here that zinc, important during mycobacterial pathogenesis, inhibits DnaB splicing in M. smegmatis Using an in vitro reporter system, we demonstrated that zinc potently and reversibly inhibited DnaBi1 splicing, as well as splicing of a comparable intein from Mycobacterium leprae Finally, in a 1.95 Å crystal structure, we show that zinc inhibits splicing through binding to the very cysteine that initiates the splicing reaction. Together, our results provide compelling support for a model whereby mycobacterial DnaB protein splicing, and thus DNA replication, is responsive to environmental zinc.IMPORTANCE Inteins are present in a large fraction of prokaryotes and localize within conserved proteins, including the mycobacterial replicative helicase DnaB. In addition to their extensive protein engineering applications, inteins have emerged as environmentally responsive posttranslational regulators of the genes that encode them. While several studies have shown compelling evidence of conditional protein splicing (CPS), examination of splicing in the native host of the intein has proven to be challenging. Here, we demonstrated through a number of measures, including the use of a splicing-dependent sensor capable of monitoring intein activity in the native host, that zinc is a potent and reversible inhibitor of mycobacterial DnaB splicing. This work also expands our knowledge of site selection for intein insertion within nonnative proteins, demonstrating that splicing-dependent host protein activation correlates with proximity to the active site. Additionally, we surmise that splicing regulation by zinc has mycobacteriocidal and CPS application potential.
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Affiliation(s)
- Daniel Woods
- Department of Biological Sciences, University at Albany, Albany, New York, USA
| | - Sweta Vangaveti
- The RNA Institute, University at Albany, Albany, New York, USA
| | - Ikechukwu Egbanum
- Department of Biological Sciences, University at Albany, Albany, New York, USA
| | - Allison M Sweeney
- Department of Biology, Murray State University, Murray, Kentucky, USA
| | - Zhong Li
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Valjean Bacot-Davis
- Renaissance School of Medicine, Stony Brook University, Stony Brook, New York, USA
| | | | - Matthew Stanger
- Department of Biological Sciences, University at Albany, Albany, New York, USA
| | | | - Hongmin Li
- Department of Biological Sciences, University at Albany, Albany, New York, USA
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Marlene Belfort
- Department of Biological Sciences, University at Albany, Albany, New York, USA
- The RNA Institute, University at Albany, Albany, New York, USA
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22
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Chiarolanzio KC, Pusztay JM, Chavez A, Zhao J, Xie J, Wang C, Mills KV. Allosteric Influence of Extremophile Hairpin Motif Mutations on the Protein Splicing Activity of a Hyperthermophilic Intein. Biochemistry 2020; 59:2459-2467. [PMID: 32559373 DOI: 10.1021/acs.biochem.0c00348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Protein splicing is a post-translational process mediated by an intein, whereby the intein excises itself from a precursor protein with concomitant ligation of the two flanking polypeptides. The intein that interrupts the DNA polymerase II in the extreme hyperthermophile Pyrococcus abyssi has a β-hairpin that extends the central β-sheet of the intein. This β-hairpin is mostly found in inteins from archaea, as well as halophilic eubacteria, and is thus called the extremophile hairpin (EXH) motif. The EXH is stabilized by multiple favorable interactions, including electrostatic interactions involving Glu29, Glu31, and Arg40. Mutations of these residues diminish the extent of N-terminal cleavage and the extent of protein splicing, likely by interfering with the coordination of the steps of splicing. These same mutations decrease the global stability of the intein fold as measured by susceptibility to thermolysin cleavage. 15N-1H heteronuclear single-quantum coherence demonstrated that these mutations altered the chemical environment of active site residues such as His93 (B-block histidine) and Ser166 (F-block residue 4). This work again underscores the connected and coordinated nature of intein conformation and dynamics, where remote mutations can disturb a finely tuned interaction network to inhibit or enhance protein splicing.
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Affiliation(s)
- Kathryn C Chiarolanzio
- Department of Chemistry, College of the Holy Cross, 1 College Street, Worcester, Massachusetts 01610, United States
| | - Jennifer M Pusztay
- Department of Chemistry, College of the Holy Cross, 1 College Street, Worcester, Massachusetts 01610, United States
| | - Angel Chavez
- Department of Chemistry, College of the Holy Cross, 1 College Street, Worcester, Massachusetts 01610, United States
| | - Jing Zhao
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Jian Xie
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Chunyu Wang
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Kenneth V Mills
- Department of Chemistry, College of the Holy Cross, 1 College Street, Worcester, Massachusetts 01610, United States
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23
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Zhang F, Zhang W. Encrypting Chemical Reactivity in Protein Sequences toward
Information‐Coded
Reactions
†. CHINESE J CHEM 2020. [DOI: 10.1002/cjoc.202000083] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Fan Zhang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry & Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University Beijing 100871 China
| | - Wen‐Bin Zhang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry & Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University Beijing 100871 China
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24
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Abstract
Split inteins are privileged molecular scaffolds for the chemical modification of proteins. Though efficient for in vitro applications, these polypeptide ligases have not been utilized for the semisynthesis of proteins in live cells. Here, we biochemically and structurally characterize the naturally split intein VidaL. We show that this split intein, which features the shortest known N-terminal fragment, supports rapid and efficient protein trans-splicing under a range of conditions, enabling semisynthesis of modified proteins both in vitro and in mammalian cells. The utility of this protein engineering system is illustrated through the traceless assembly of multidomain proteins whose biophysical properties render them incompatible with a single expression system, as well as by the semisynthesis of dual posttranslationally modified histone proteins in live cells. We also exploit the domain swapping function of VidaL to effect simultaneous modification and translocation of the nuclear protein HP1α in live cells. Collectively, our studies highlight the VidaL system as a tool for the precise chemical modification of cellular proteins with spatial and temporal control.
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25
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Abstract
Protein semisynthesis-defined herein as the assembly of a protein from a combination of synthetic and recombinant fragments-is a burgeoning field of chemical biology that has impacted many areas in the life sciences. In this review, we provide a comprehensive survey of this area. We begin by discussing the various chemical and enzymatic methods now available for the manufacture of custom proteins containing noncoded elements. This section begins with a discussion of methods that are more chemical in origin and ends with those that employ biocatalysts. We also illustrate the commonalities that exist between these seemingly disparate methods and show how this is allowing for the development of integrated chemoenzymatic methods. This methodology discussion provides the technical foundation for the second part of the review where we cover the great many biological problems that have now been addressed using these tools. Finally, we end the piece with a short discussion on the frontiers of the field and the opportunities available for the future.
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Affiliation(s)
| | - Tom W. Muir
- Department of Chemistry, Princeton University, Frick Laboratory, Princeton, New Jersey 08544, United States
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26
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Zhang M, Zhang Y, Wu B, Peng Y, Simair AA, Siegel GW, Lu C, Chen T. Intein-mediated recombinant expression of monomeric B22Asp desB30 insulin. BMC Biotechnol 2020; 20:3. [PMID: 31918694 PMCID: PMC6953245 DOI: 10.1186/s12896-020-0598-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Accepted: 01/03/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Insulin controls hyperglycemia caused by diabetes, and virtually all treatments require exogenous insulin. However, the product's extensive post-translational modifications have hindered the manufacture of recombinant insulin. RESULT Here we report a novel production method for a monomeric B22Asp desB30 insulin analog (B22D desB30 insulin). Its precursor, DPIP, is fused to an N-terminal chitin-binding domain and intein self-cleavage tag. The fusion protein is expressed and purified from E. coli and immobilized on chitin resins. DPIP is then released using an optimized pH shift and converted to mature insulin via trypsin digest. The resulting product appears monomeric, > 90% pure and devoid of any exogenous enzyme. CONCLUSION Thus, biologically active insulin analog can be efficiently produced in bacteria and potentially applicable in the treatment of human diabetes.
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Affiliation(s)
- Minmin Zhang
- Key Laboratory of Science and Technology of Eco-Textiles, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, 2999 North Ren Min Rd, Shanghai, 201620, China
| | - Yunlong Zhang
- Key Laboratory of Science and Technology of Eco-Textiles, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, 2999 North Ren Min Rd, Shanghai, 201620, China
| | - Bingnan Wu
- Key Laboratory of Science and Technology of Eco-Textiles, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, 2999 North Ren Min Rd, Shanghai, 201620, China
| | - Yanhao Peng
- Key Laboratory of Science and Technology of Eco-Textiles, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, 2999 North Ren Min Rd, Shanghai, 201620, China
| | - Altaf Ahmed Simair
- Key Laboratory of Science and Technology of Eco-Textiles, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, 2999 North Ren Min Rd, Shanghai, 201620, China
| | - Geoffery W Siegel
- Department of Orthopaedic Surgery, Musculoskeletal Oncology Division, University of Michigan Medical School, Ann Arbor, MI, 10, USA
| | - Changrui Lu
- Key Laboratory of Science and Technology of Eco-Textiles, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, 2999 North Ren Min Rd, Shanghai, 201620, China.
| | - Ting Chen
- Key Laboratory of Science and Technology of Eco-Textiles, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, 2999 North Ren Min Rd, Shanghai, 201620, China.
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27
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Zhao J, Du Z, Wang C, Mills KV. Methods to Study the Structure and Catalytic Activity of cis-Splicing Inteins. Methods Mol Biol 2020; 2133:55-73. [PMID: 32144663 PMCID: PMC7325523 DOI: 10.1007/978-1-0716-0434-2_4] [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] [Indexed: 05/26/2024]
Abstract
The autocatalytic process of protein splicing is facilitated by an intein, which interrupts flanking polypeptides called exteins. The mechanism of protein splicing has been studied by overexpression in E. coli of intein fusion proteins with nonnative exteins. Inteins can be used to generate reactive α-thioesters, as well as proteins with N-terminal Cys residues, to facilitate expressed protein ligation. As such, a more detailed understanding of the function of inteins can have significant impact for biotechnology applications. Here, we provide biochemical methods to study splicing activity and NMR methods to study intein structure and the catalytic mechanism.
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Affiliation(s)
- Jing Zhao
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Zhenming Du
- Department of Chemistry, Georgia State University, Atlanta, GA, USA
| | - Chunyu Wang
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Kenneth V Mills
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA.
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28
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Farrelly LA, Maze I. An emerging perspective on 'histone code' mediated regulation of neural plasticity and disease. Curr Opin Neurobiol 2019; 59:157-163. [PMID: 31382083 PMCID: PMC6889037 DOI: 10.1016/j.conb.2019.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 07/07/2019] [Indexed: 12/19/2022]
Abstract
The last two decades have witnessed explosive advances in our understanding as to how the organization of chromatin, the association of DNA with histones and vast numbers of non-histone regulatory proteins, controls the expression of specific genes in brain. Prominent among such regulatory mechanisms are modifications of histones, along with the 'writers,' 'erasers,' and 'readers' of these modifications. Much of the work delineating these mechanisms has contributed to the idea that a 'histone code' may be a central determinant of a gene's activity and its potential to be activated or repressed in response to environmental perturbations (both beneficial and aberrant). Indeed, increasing evidence has demonstrated the significance of histone regulation in neurological plasticity and disease, although we are still at the earliest stages of examining all of the many potential chromatin changes involved. In this short review, we provide an emerging perspective on putative roles for histones, and their combinatorial readouts, in the context of neural plasticity, and we provide a conceptual framework for future mechanistic studies aimed at uncovering causal links between the neural 'histone code' and brain function/disease.
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Affiliation(s)
- Lorna A Farrelly
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Ian Maze
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States; Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
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Cieplak AS. Tau Inclusions in Alzheimer's, Chronic Traumatic Encephalopathy and Pick's Disease. A Speculation on How Differences in Backbone Polarization Underlie Divergent Pathways of Tau Aggregation. Front Neurosci 2019; 13:488. [PMID: 31156372 PMCID: PMC6530265 DOI: 10.3389/fnins.2019.00488] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 04/29/2019] [Indexed: 12/13/2022] Open
Abstract
Tau-related dementias appear to involve specific to each disease aggregation pathways and morphologies of filamentous tau assemblies. To understand etiology of these differences, here we elucidate molecular mechanism of formation of tau PHFs based on the PMO theory of misfolding and aggregation of pleiomorphic proteins associated with neurodegenerative diseases. In this model, fibrillization of tau is initiated by the coupled binding and folding of the MTB domains that yields antiparallel homodimers, in analogy to folding of split inteins. The free energy of binding is minimized when the antiparallel alignment brings about backbone-backbone H-bonding between the MTBD segments of similar "strand" propensities. To assess these propensities, a function of the NMR shielding tensors of the Cα atoms is introduced as the folding potential function FP i ; the Cα tensors are obtained by the quantum mechanical modeling of protein secondary structure (GIAO//B3LYP/D95**). The calculated FP i plots show that the "strand" propensities of the MBTD segments, and hence the homodimer's register, can be affected by the relatively small changes in the environment's pH, as a result of protonation of MBTD's conserved histidines. The assembly of the antiparallel tau dimers into granular aggregates and their subsequent conversion into the parallel cross-β structure of paired helical filaments is expected to follow the same path as the previously described fibrillization of Aβ. Consequently, the core structure of the nascent tau fibril is determined by the register of the tau homodimer. This model accounts for the reported differences in (i) fibril-core structure of in vivo and in vitro filaments, (ii) cross-seeding of isoforms, (iii) effects of reducing/non-reducing conditions, (iv) effects of PHF6 mutations, and (v) homologs' aggregation properties. The proposed model also suggests that in contrast to Alzheimer's and chronic traumatic encephalopathy disease, the assembly of tau prions in Pick's disease would be facilitated by a moderate drop in pH that accompanies e.g., transit in the endosomal system, inflammation response or an ischemic injury.
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Affiliation(s)
- Andrzej Stanisław Cieplak
- Department of Chemistry, Bilkent University, Ankara, Turkey
- Department of Chemistry, Yale University, New Haven, CT, United States
- Department of Chemistry, Brandeis University, Waltham, MA, United States
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Different forms of African cassava mosaic virus capsid protein within plants and virions. Virology 2019; 529:81-90. [PMID: 30684693 DOI: 10.1016/j.virol.2019.01.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/14/2019] [Accepted: 01/16/2019] [Indexed: 01/04/2023]
Abstract
One geminiviral gene encodes the capsid protein (CP), which can appear as several bands after electrophoresis depending on virus and plant. African cassava mosaic virus-Nigeria CP in Nicotiana benthamiana, however, yielded one band (~ 30 kDa) in total protein extracts and purified virions, although its expression in yeast yielded two bands (~ 30, 32 kDa). Mass spectrometry of the complete protein and its tryptic fragments from virions is consistent with a cleaved start M1, acetylated S2, and partial phosphorylation at T12, S25 and S62. Mutants for additional potentially modified sites (N223A; C235A) were fully infectious and formed geminiparticles. Separation in triton acetic acid urea gels confirmed charge changes of the CP between plants and yeast indicating differential phosphorylation. If the CP gene alone was expressed in plants, multiple bands were observed like in yeast. A high turnover rate indicates that post-translational modifications promote CP decay probably via the ubiquitin-triggered proteasomal pathway.
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Li Z, Fu B, Green CM, Liu B, Zhang J, Lang Y, Chaturvedi S, Belfort M, Liao G, Li H. Cisplatin protects mice from challenge of Cryptococcus neoformans by targeting the Prp8 intein. Emerg Microbes Infect 2019; 8:895-908. [PMID: 31223062 PMCID: PMC6598491 DOI: 10.1080/22221751.2019.1625727] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 05/16/2019] [Indexed: 01/02/2023]
Abstract
The Prp8 intein is one of the most widespread eukaryotic inteins, present in important pathogenic fungi, including Cryptococcus and Aspergillus species. Because the processed Prp8 carries out essential and non-redundant cellular functions, a Prp8 intein inhibitor is a mechanistically novel antifungal agent. In this report, we demonstrated that cisplatin, an FDA-approved cancer drug, significantly arrested growth of Prp8 intein-containing fungi C. neoformans and C. gattii, but only poorly inhibited growth of intein-free Candida species. These results suggest that cisplatin arrests fungal growth through specific inhibition of the Prp8 intein. Cisplatin was also found to significantly inhibit growth of C. neoformans in a mouse model. Our results further showed that cisplatin inhibited Prp8 intein splicing in vitro in a dose-dependent manner by direct binding to the Prp8 intein. Crystal structures of the apo- and cisplatin-bound Prp8 inteins revealed that two degenerate cisplatin molecules bind at the intein active site. Mutation of the splicing-site residues led to loss of cisplatin binding, as well as impairment of intein splicing. Finally, we found that overexpression of the Prp8 intein in cryptococcal species conferred cisplatin resistance. Overall, these results indicate that the Prp8 intein is a novel antifungal target worth further investigation.
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Affiliation(s)
- Zhong Li
- New York State Department of Health, Wadsworth Center, Albany, NY, USA
| | - Bin Fu
- College of Pharmaceutical Sciences, Southwest University, Chongqing, People’s Republic of China
| | - Cathleen M. Green
- Department of Biological Sciences and RNA Institute, University at Albany, Albany, NY, USA
| | - Binbin Liu
- New York State Department of Health, Wadsworth Center, Albany, NY, USA
| | - Jing Zhang
- New York State Department of Health, Wadsworth Center, Albany, NY, USA
| | - Yuekun Lang
- New York State Department of Health, Wadsworth Center, Albany, NY, USA
| | - Sudha Chaturvedi
- New York State Department of Health, Wadsworth Center, Albany, NY, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, USA
| | - Marlene Belfort
- Department of Biological Sciences and RNA Institute, University at Albany, Albany, NY, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, USA
| | - Guojian Liao
- College of Pharmaceutical Sciences, Southwest University, Chongqing, People’s Republic of China
| | - Hongmin Li
- New York State Department of Health, Wadsworth Center, Albany, NY, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, USA
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Kelley DS, Lennon CW, Li Z, Miller MR, Banavali NK, Li H, Belfort M. Mycobacterial DnaB helicase intein as oxidative stress sensor. Nat Commun 2018; 9:4363. [PMID: 30341292 PMCID: PMC6195587 DOI: 10.1038/s41467-018-06554-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 09/10/2018] [Indexed: 11/09/2022] Open
Abstract
Inteins are widespread self-splicing protein elements emerging as potential post-translational environmental sensors. Here, we describe two inteins within one protein, the Mycobacterium smegmatis replicative helicase DnaB. These inteins, DnaBi1 and DnaBi2, have homology to inteins in pathogens, splice with vastly varied rates, and are differentially responsive to environmental stressors. Whereas DnaBi1 splicing is reversibly inhibited by oxidative and nitrosative insults, DnaBi2 is not. Using a reporter that measures splicing in a native intein-containing organism and western blotting, we show that H2O2 inhibits DnaBi1 splicing in M. smegmatis. Intriguingly, upon oxidation, the catalytic cysteine of DnaBi1 forms an intramolecular disulfide bond. We report a crystal structure of the class 3 DnaBi1 intein at 1.95 Å, supporting our findings and providing insight into this splicing mechanism. We propose that this cysteine toggle allows DnaBi1 to sense stress, pausing replication to maintain genome integrity, and then allowing splicing immediately when permissive conditions return.
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Affiliation(s)
- Danielle S Kelley
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, 12222, USA
| | - Christopher W Lennon
- Department of Biological Sciences and RNA Institute, University at Albany, Albany, NY, 12222, USA
| | - Zhong Li
- Wadsworth Center, New York State Department of Health, 120 New Scotland Ave, Albany, NY, 12208, USA
| | - Michael R Miller
- Department of Chemistry, University at Albany, Albany, NY, 12222, USA
| | - Nilesh K Banavali
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, 12222, USA
- Wadsworth Center, New York State Department of Health, 120 New Scotland Ave, Albany, NY, 12208, USA
| | - Hongmin Li
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, 12222, USA.
- Wadsworth Center, New York State Department of Health, 120 New Scotland Ave, Albany, NY, 12208, USA.
| | - Marlene Belfort
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, 12222, USA.
- Department of Biological Sciences and RNA Institute, University at Albany, Albany, NY, 12222, USA.
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Stevens AJ, Sekar G, Gramespacher JA, Cowburn D, Muir TW. An Atypical Mechanism of Split Intein Molecular Recognition and Folding. J Am Chem Soc 2018; 140:11791-11799. [PMID: 30156841 PMCID: PMC7232844 DOI: 10.1021/jacs.8b07334] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Split inteins associate to trigger protein splicing in trans, a post-translational modification in which protein sequences fused to the intein pair are ligated together in a traceless manner. Recently, a family of naturally split inteins has been identified that is split at a noncanonical location in the primary sequence. These atypically split inteins show considerable promise in protein engineering applications; however, the mechanism by which they associate is unclear and must be different from that of previously characterized canonically split inteins due to unique topological restrictions. Here, we use a consensus design strategy to generate an atypical split intein pair (Cat) that has greatly improved activity and is amenable to detailed biochemical and biophysical analysis. Guided by the solution structure of Cat, we show that the association of the fragments involves a disorder-to-order structural transition driven by hydrophobic interactions. This molecular recognition mechanism satisfies the topological constraints of the intein fold and, importantly, ensures that premature chemistry does not occur prior to fragment complementation. Our data lead a common blueprint for split intein complementation in which localized structural rearrangements are used to drive folding and regulate protein-splicing activity.
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Affiliation(s)
- Adam J. Stevens
- Department of Chemistry, Princeton University, Frick Laboratory, Princeton, New Jersey 08544, United States
| | - Giridhar Sekar
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| | - Josef A. Gramespacher
- Department of Chemistry, Princeton University, Frick Laboratory, Princeton, New Jersey 08544, United States
| | - David Cowburn
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, United States
| | - Tom W. Muir
- Department of Chemistry, Princeton University, Frick Laboratory, Princeton, New Jersey 08544, United States
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Abstract
Chromatin-related phenomena regulate gene expression by altering the compaction and accessibility of DNA to relevant transcription factors, thus allowing every cell in the body to attain distinct identities and to function properly within a given cellular context. These processes occur not only in the developing central nervous system, but continue throughout the lifetime of a neuron to constantly adapt to changes in the environment. Such changes can be positive or negative, thereby altering the chromatin landscape to influence cellular and synaptic plasticity within relevant neural circuits, and ultimately behavior. Given the importance of epigenetic mechanisms in guiding physiological adaptations, perturbations in these processes in brain have been linked to several neuropsychiatric and neurological disorders. In this review, we cover some of the recent advances linking chromatin dynamics to complex brain disorders and discuss new methodologies that may overcome current limitations in the field.
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Affiliation(s)
- Ryan M Bastle
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Ian Maze
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029.,Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029
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Garcia Garces H, Cordeiro RT, Bagagli E. PRP8 intein in dermatophytes: Evolution and species identification. Med Mycol 2018; 56:746-758. [PMID: 29228309 DOI: 10.1093/mmy/myx102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 09/27/2017] [Indexed: 11/14/2022] Open
Abstract
Dermatophytes are keratinophilic fungi belonging to the family Arthrodermataceae. Despite having a monophyletic origin, its systematics has always been complex and controversial. Sequencing of nuclear ribosomal ITS and D1/D2 rDNA has been proposed as an efficient tool for identifying species in this group of fungi, while multilocus analyses have been used for phylogenetic species recognition. However, the search for new markers, with sequence and size variation, which enable species identification in only one polymerase chain reaction (PCR) step, is very attractive. Inteins seems to fulfill these characteristics. They are self-splicing genetic elements present within housekeeping coding genes, such as PRP8, that codify the most important protein of the spliceosome. The PRP8 intein has been described for Microsporum canis in databases but has not been studied in dermatophytes in any other published work. Thus, our aim was to determine the potential of this intervening element for establishing phylogenetic relationships among dermatophytes and for identifying species. It was found that all studied species have a full-length PRP8 intein with a Homing Endonuclease belonging to the family LAGLIDADG. Phylogenetic analyses were consistent with other previous phylogenies, confirming Epidermophyton floccosum in the same clade of the Arthroderma gypseum complex, Microsporum audouinii close to M. canis, differentiating A. gypseum from Arthroderma incurvatum, and in addition, better defining the Trichophyton interdigitale and Trichophyton rubrum species grouping. Length polymorphism in the HE region enables identification of the most relevant Microsporum species by a simple PCR-electrophoresis assay. Intein PRP8 within dermatophytes is a powerful additional tool for identifying and systematizing dermatophytes.
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Affiliation(s)
- Hans Garcia Garces
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual de São Paulo. São Paulo. Brasil
| | - Raquel Theodoro Cordeiro
- Instituto de Medicina Tropical do RN, Universidade Federal de Rio Grande do Norte. Rio Grande do Norte. Brasil
| | - E Bagagli
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual de São Paulo. São Paulo. Brasil
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Structural insights into the backbone-circularized granulocyte colony-stimulating factor containing a short connector. Biochem Biophys Res Commun 2018; 500:224-228. [DOI: 10.1016/j.bbrc.2018.04.045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 04/06/2018] [Indexed: 11/21/2022]
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37
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Gordo V, Aparicio D, Pérez-Luque R, Benito A, Vilanova M, Usón I, Fita I, Ribó M. Structural Insights into Subunits Assembly and the Oxyester Splicing Mechanism of Neq pol Split Intein. Cell Chem Biol 2018; 25:871-879.e2. [PMID: 29754955 DOI: 10.1016/j.chembiol.2018.04.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/28/2018] [Accepted: 04/08/2018] [Indexed: 11/28/2022]
Abstract
Split inteins are expressed as two separated subunits (N-intein and C-intein) fused to the corresponding exteins. The specific association of both intein subunits precedes protein splicing, which results in excision of the intein subunits and in ligation, by a peptide bond, of the concomitant exteins. Catalytically active intein precursors are typically too reactive for crystallization or even isolation. Neq pol is the trans-intein of the B-type DNA polymerase I split gene from hyperthermophile Nanoarchaeum equitans. We have determined the crystal structures of both the isolated NeqN and the complex of NeqN and NeqC subunits carrying the wild-type sequences, including the essential catalytic residues Ser1 and Thr+1, in addition to seven and three residues of the N- and C-exteins, respectively. These structures provide detailed information on the unique oxyester chemistry of the splicing mechanism of Neq pol and of the extensive rearrangements that occur in NeqN during the association step.
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Affiliation(s)
- Verónica Gordo
- Laboratori d'Enginyeria de Proteïnes, Departament de Biologia, Facultat de Ciències, Universitat de Girona, C/ Maria Aurèlia Capmany 40, 17003 Girona, Spain; IdIBGi Hospital Universitari Josep Trueta, Girona, Spain
| | - David Aparicio
- Instituto de Biología Molecular de Barcelona (IBMB-CSIC), Parc Cientific de Barcelona, Baldiri i Reixac 10, 08028 Barcelona, Spain
| | - Rosa Pérez-Luque
- Instituto de Biología Molecular de Barcelona (IBMB-CSIC), Parc Cientific de Barcelona, Baldiri i Reixac 10, 08028 Barcelona, Spain
| | - Antoni Benito
- Laboratori d'Enginyeria de Proteïnes, Departament de Biologia, Facultat de Ciències, Universitat de Girona, C/ Maria Aurèlia Capmany 40, 17003 Girona, Spain; IdIBGi Hospital Universitari Josep Trueta, Girona, Spain
| | - Maria Vilanova
- Laboratori d'Enginyeria de Proteïnes, Departament de Biologia, Facultat de Ciències, Universitat de Girona, C/ Maria Aurèlia Capmany 40, 17003 Girona, Spain; IdIBGi Hospital Universitari Josep Trueta, Girona, Spain
| | - Isabel Usón
- Instituto de Biología Molecular de Barcelona (IBMB-CSIC), Parc Cientific de Barcelona, Baldiri i Reixac 10, 08028 Barcelona, Spain; ICREA Lluís Companys 23, 08003 Barcelona, Spain
| | - Ignacio Fita
- Instituto de Biología Molecular de Barcelona (IBMB-CSIC), Parc Cientific de Barcelona, Baldiri i Reixac 10, 08028 Barcelona, Spain.
| | - Marc Ribó
- Laboratori d'Enginyeria de Proteïnes, Departament de Biologia, Facultat de Ciències, Universitat de Girona, C/ Maria Aurèlia Capmany 40, 17003 Girona, Spain; IdIBGi Hospital Universitari Josep Trueta, Girona, Spain.
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Cieplak AS. Protein folding, misfolding and aggregation: The importance of two-electron stabilizing interactions. PLoS One 2017; 12:e0180905. [PMID: 28922400 PMCID: PMC5603215 DOI: 10.1371/journal.pone.0180905] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 06/22/2017] [Indexed: 12/17/2022] Open
Abstract
Proteins associated with neurodegenerative diseases are highly pleiomorphic and may adopt an all-α-helical fold in one environment, assemble into all-β-sheet or collapse into a coil in another, and rapidly polymerize in yet another one via divergent aggregation pathways that yield broad diversity of aggregates’ morphology. A thorough understanding of this behaviour may be necessary to develop a treatment for Alzheimer’s and related disorders. Unfortunately, our present comprehension of folding and misfolding is limited for want of a physicochemical theory of protein secondary and tertiary structure. Here we demonstrate that electronic configuration and hyperconjugation of the peptide amide bonds ought to be taken into account to advance such a theory. To capture the effect of polarization of peptide linkages on conformational and H-bonding propensity of the polypeptide backbone, we introduce a function of shielding tensors of the Cα atoms. Carrying no information about side chain-side chain interactions, this function nonetheless identifies basic features of the secondary and tertiary structure, establishes sequence correlates of the metamorphic and pH-driven equilibria, relates binding affinities and folding rate constants to secondary structure preferences, and manifests common patterns of backbone density distribution in amyloidogenic regions of Alzheimer’s amyloid β and tau, Parkinson’s α-synuclein and prions. Based on those findings, a split-intein like mechanism of molecular recognition is proposed to underlie dimerization of Aβ, tau, αS and PrPC, and divergent pathways for subsequent association of dimers are outlined; a related mechanism is proposed to underlie formation of PrPSc fibrils. The model does account for: (i) structural features of paranuclei, off-pathway oligomers, non-fibrillar aggregates and fibrils; (ii) effects of incubation conditions, point mutations, isoform lengths, small-molecule assembly modulators and chirality of solid-liquid interface on the rate and morphology of aggregation; (iii) fibril-surface catalysis of secondary nucleation; and (iv) self-propagation of infectious strains of mammalian prions.
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Affiliation(s)
- Andrzej Stanisław Cieplak
- Department of Chemistry, Bilkent University, Ankara, Turkey
- Department of Chemistry, Yale University, New Haven, Connecticut, United States of America
- Department of Chemistry, Brandeis University, Waltham, Massachusetts, United States of America
- * E-mail:
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Ramsoomair CK, Yakely AE, Urbanski LM, Karanja K, Giaccone ZT, Siegart NM, Wang C, Gomez AV, Reitter JN, Mills KV. Coordination of the third step of protein splicing in two cyanobacterial inteins. FEBS Lett 2017. [PMID: 28649707 DOI: 10.1002/1873-3468.12730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The third step of protein splicing is cyclization of Asn coupled to peptide bond cleavage. In two related cyanobacterial inteins, this step is facilitated by Asn or Gln. For a Synechococcus sp. PCC7002 intein, the isolated third step of protein splicing is more efficient with its native Asn than with substitution to Gln. For a Trichodesmium erythraeum intein, its native Gln facilitates the third step as efficiently as with Asn. Despite these differences, the yield of splicing is not affected, suggesting that the third step is influenced by mechanism-linked conformational changes. A conserved catalytic His and the penultimate residue also play roles in promoting side-chain cyclization.
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Affiliation(s)
| | - Anthony E Yakely
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA
| | - Laura M Urbanski
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA
| | - Kevin Karanja
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA
| | | | - Nicolle M Siegart
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA
| | - Chunyu Wang
- Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA.,Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Alvin V Gomez
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA
| | - Julie N Reitter
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA
| | - Kenneth V Mills
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA
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Burke HM, McSweeney L, Scanlan EM. Exploring chemoselective S-to-N acyl transfer reactions in synthesis and chemical biology. Nat Commun 2017; 8:15655. [PMID: 28537277 PMCID: PMC5458133 DOI: 10.1038/ncomms15655] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 04/13/2017] [Indexed: 12/16/2022] Open
Abstract
S -to-N acyl transfer is a high-yielding chemoselective process for amide bond formation. It is widely utilized by chemists for synthetic applications, including peptide and protein synthesis, chemical modification of proteins, protein-protein ligation and the development of probes and molecular machines. Recent advances in our understanding of S -to-N acyl transfer processes in biology and innovations in methodology for thioester formation and desulfurization, together with an extension of the size of cyclic transition states, have expanded the boundaries of this process well beyond peptide ligation. As the field develops, this chemistry will play a central role in our molecular understanding of Biology. The conversion of thioesters to amides via acyl transfer has become one of the most important synthetic techniques for the chemical synthesis and modification of proteins. This review discusses this S-to-N acyl transfer process, and highlights some of the key applications across chemistry and biology.
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Affiliation(s)
- Helen M. Burke
- School of Chemistry, Trinity College Dublin, Dublin D2, Ireland
| | | | - Eoin M. Scanlan
- School of Chemistry, Trinity College Dublin, Dublin D2, Ireland
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43
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Conditional Toxin Splicing Using a Split Intein System. Methods Mol Biol 2016. [PMID: 27714618 DOI: 10.1007/978-1-4939-6451-2_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Protein toxin splicing mediated by split inteins can be used as a strategy for conditional cell ablation. The approach requires artificial fragmentation of a potent protein toxin and tethering each toxin fragment to a split intein fragment. The toxin-intein fragments are, in turn, fused to dimerization domains, such that addition of a dimerizing agent reconstitutes the split intein. These chimeric toxin-intein fusions remain nontoxic until the dimerizer is added, resulting in activation of intein splicing and ligation of toxin fragments to form an active toxin. Considerations for the engineering and implementation of conditional toxin splicing (CTS) systems include: choice of toxin split site, split site (extein) chemistry, and temperature sensitivity. The following method outlines design criteria and implementation notes for CTS using a previously engineered system for splicing a toxin called sarcin, as well as for developing alternative CTS systems.
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Tori K, Perler F. Sequential formation of two branched intermediates during protein splicing of class three inteins. Extremophiles 2016; 21:41-49. [PMID: 27704298 PMCID: PMC5222942 DOI: 10.1007/s00792-016-0876-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 09/24/2016] [Indexed: 11/25/2022]
Abstract
Inteins are the protein equivalent of introns. They are seamlessly removed during post-translational maturation of their host protein (extein). Inteins from extremophiles played a key role in understanding intein-mediated protein splicing. There are currently three classes of inteins defined by catalytic mechanism and sequence signatures. This study demonstrates splicing of three class 3 mini-inteins: Burkholderia vietnamiensis G4 Bvi IcmO intein, Mycobacterium smegmatis MC2 155 Msm DnaB-1 intein and Mycobacterium leprae strain TN Mle DnaB intein. B. vietnamiensis has a broad ecological range and remediates trichloroethene. M. smegmatis is a biofilm forming soil bacteria. Although other intein classes have only a single branched intermediate at the C-terminal splice junction, the class 3 intein reaction pathway includes two branched intermediates. The class 3 specific branched intermediate is formed by an internal cysteine, while the C-terminal branch intermediate is at a serine or threonine in all class 3 inteins except the Bvi IcmO intein, where it is a cysteine. This latter cysteine was unable to compensate for mutation of the class 3-specific internal catalytic cysteine despite the Bvi IcmO intein having an N-terminal splice junction naturally tuned for a cysteine nucleophile, demonstrating the mandatory order of branch intermediates in class 3 inteins.
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Affiliation(s)
- Kazuo Tori
- New England Biolabs, Inc., Ipswich, MA 01938 USA
- Takara Bio USA, Inc., 1290 Terra Bella Ave., Mountain View, CA 94043 USA
| | - Francine Perler
- New England Biolabs, Inc., Ipswich, MA 01938 USA
- Perls of Wisdom Biotech Consulting, Brookline, MA 02446 USA
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520 USA
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Chan H, Pearson CS, Green CM, Li Z, Zhang J, Belfort G, Shekhtman A, Li H, Belfort M. Exploring Intein Inhibition by Platinum Compounds as an Antimicrobial Strategy. J Biol Chem 2016; 291:22661-22670. [PMID: 27609519 DOI: 10.1074/jbc.m116.747824] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 08/29/2016] [Indexed: 01/10/2023] Open
Abstract
Inteins, self-splicing protein elements, interrupt genes and proteins in many microbes, including the human pathogen Mycobacterium tuberculosis Using conserved catalytic nucleophiles at their N- and C-terminal splice junctions, inteins are able to excise out of precursor polypeptides. The splicing of the intein in the mycobacterial recombinase RecA is specifically inhibited by the widely used cancer therapeutic cisplatin, cis-[Pt(NH3)2Cl2], and this compound inhibits mycobacterial growth. Mass spectrometric and crystallographic studies of Pt(II) binding to the RecA intein revealed a complex in which two platinum atoms bind at N- and C-terminal catalytic cysteine residues. Kinetic analyses of NMR spectroscopic data support a two-step binding mechanism in which a Pt(II) first rapidly interacts reversibly at the N terminus followed by a slower, first order irreversible binding event involving both the N and C termini. Notably, the ligands of Pt(II) compounds that are required for chemotherapeutic efficacy and toxicity are no longer bound to the metal atom in the intein adduct. The lack of ammine ligands and need for phosphine represent a springboard for future design of platinum-based compounds targeting inteins. Because the intein splicing mechanism is conserved across a range of pathogenic microbes, developing these drugs could lead to novel, broad range antimicrobial agents.
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Affiliation(s)
- Hon Chan
- From the Department of Biological Sciences and RNA Institute and.,Howard P. Isermann Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180
| | - C Seth Pearson
- From the Department of Biological Sciences and RNA Institute and.,Howard P. Isermann Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180
| | - Cathleen M Green
- From the Department of Biological Sciences and RNA Institute and
| | - Zhong Li
- Laboratory of Computational and Structural Biology, Wadsworth Center, New York State Department of Health, Albany, New York 12208, and
| | - Jing Zhang
- Laboratory of Computational and Structural Biology, Wadsworth Center, New York State Department of Health, Albany, New York 12208, and
| | - Georges Belfort
- Howard P. Isermann Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180
| | - Alex Shekhtman
- Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222
| | - Hongmin Li
- Laboratory of Computational and Structural Biology, Wadsworth Center, New York State Department of Health, Albany, New York 12208, and.,Department of Biomedical Sciences, University at Albany, State University of New York, Albany, New York 12201
| | - Marlene Belfort
- From the Department of Biological Sciences and RNA Institute and
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46
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Weichert N, Hauptmann V, Helmold C, Conrad U. Seed-Specific Expression of Spider Silk Protein Multimers Causes Long-Term Stability. FRONTIERS IN PLANT SCIENCE 2016; 7:6. [PMID: 26858734 PMCID: PMC4729946 DOI: 10.3389/fpls.2016.00006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/06/2016] [Indexed: 05/26/2023]
Abstract
Seeds enable plants to germinate and to grow in situations of limited availability of nutrients. The stable storage of different seed proteins is a remarkable presumption for successful germination and growth. These strategies have been adapted and used in several molecular farming projects. In this study, we explore the benefits of seed-based expression to produce the high molecular weight spider silk protein FLAG using intein-based trans-splicing. Multimers larger than 460 kDa in size are routinely produced, which is above the native size of the FLAG protein. The storage of seeds for 8 weeks and 1 year at an ambient temperature of 15°C does not influence the accumulation level. Even the extended storage time does not influence the typical pattern of multimerized bands. These results show that seeds are the method of choice for stable accumulation of products of complex transgenes and have the capability for long-term storage at moderate conditions, an important feature for the development of suitable downstream processes.
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47
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Meyers PR. Analysis of recombinase A (recA/RecA) in the actinobacterial family Streptosporangiaceae and identification of molecular signatures. Syst Appl Microbiol 2015; 38:567-77. [DOI: 10.1016/j.syapm.2015.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 09/28/2015] [Accepted: 10/02/2015] [Indexed: 12/23/2022]
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48
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Cronin M, Coolbaugh MJ, Nellis D, Zhu J, Wood DW, Nussinov R, Ma B. Dynamics differentiate between active and inactive inteins. Eur J Med Chem 2015; 91:51-62. [PMID: 25087201 PMCID: PMC4308580 DOI: 10.1016/j.ejmech.2014.07.094] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 07/21/2014] [Accepted: 07/25/2014] [Indexed: 11/29/2022]
Abstract
The balance between stability and dynamics for active enzymes can be somewhat quantified by studies of intein splicing and cleaving reactions. Inteins catalyze the ligation of flanking host exteins while excising themselves. The potential for applications led to engineering of a mini-intein splicing domain, where the homing endonuclease domain of the Mycobacterium tuberculosis RecA (Mtu recA) intein was removed. The remaining domains were linked by several short peptides, but splicing activity in all was substantially lower than the full-length intein. Native splicing activity was restored in some cases by a V67L mutation. Using computations and experiments, we examine the impact of this mutation on the stability and conformational dynamics of the mini-intein splicing domain. Molecular dynamics simulations were used to delineate the factors that determine the active state, including the V67L mini-intein mutant, and peptide linker. We found that (1) the V67L mutation lowers the global fluctuations in all modeled mini-inteins, stabilizing the mini-intein constructs; (2) the connecting linker length affects intein dynamics; and (3) the flexibilities of the linker and intein core are higher in the active structure. We have observed that the interaction of the linker region and a turn region around residues 35-41 provides the pathway for the allostery interaction. Our experiments reveal that intein catalysis is characterized by non-linear Arrhenius plot, confirming the significant contribution of protein conformational dynamics to intein function. We conclude that while the V67L mutation stabilizes the global structure, cooperative dynamics of all intein regions appear more important for intein function than high stability. Our studies suggest that effectively quenching the conformational dynamics of an intein through engineered allosteric interactions could deactivate intein splicing or cleaving.
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Affiliation(s)
- Melissa Cronin
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, USA
| | - Michael J Coolbaugh
- Department of Chemical and Biomolecular Engineering, Ohio State University, Columbus, OH 43210, USA
| | - David Nellis
- Biopharmaceutical Development Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Jianwei Zhu
- School of Pharmacy, Shanghai Jiao Tong University, 800 DongChuan Road, Shanghai 200240, China
| | - David W Wood
- Department of Chemical and Biomolecular Engineering, Ohio State University, Columbus, OH 43210, USA
| | - Ruth Nussinov
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, USA; Sackler Inst. of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Buyong Ma
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, USA.
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Karp JM, Erylimaz E, Cowburn D. Correlation of chemical shifts predicted by molecular dynamics simulations for partially disordered proteins. JOURNAL OF BIOMOLECULAR NMR 2015; 61:35-45. [PMID: 25416617 PMCID: PMC4715900 DOI: 10.1007/s10858-014-9879-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 11/17/2014] [Indexed: 06/04/2023]
Abstract
There has been a longstanding interest in being able to accurately predict NMR chemical shifts from structural data. Recent studies have focused on using molecular dynamics (MD) simulation data as input for improved prediction. Here we examine the accuracy of chemical shift prediction for intein systems, which have regions of intrinsic disorder. We find that using MD simulation data as input for chemical shift prediction does not consistently improve prediction accuracy over use of a static X-ray crystal structure. This appears to result from the complex conformational ensemble of the disordered protein segments. We show that using accelerated molecular dynamics (aMD) simulations improves chemical shift prediction, suggesting that methods which better sample the conformational ensemble like aMD are more appropriate tools for use in chemical shift prediction for proteins with disordered regions. Moreover, our study suggests that data accurately reflecting protein dynamics must be used as input for chemical shift prediction in order to correctly predict chemical shifts in systems with disorder.
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Affiliation(s)
- Jerome M. Karp
- Department of Biochemistry, Albert Einstein College of, Medicine of Yeshiva University, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Ertan Erylimaz
- Department of Biochemistry, Albert Einstein College of, Medicine of Yeshiva University, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - David Cowburn
- Department of Biochemistry, Albert Einstein College of, Medicine of Yeshiva University, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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50
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Cheriyan M, Chan SH, Perler F. Traceless splicing enabled by substrate-induced activation of the Nostoc punctiforme Npu DnaE intein after mutation of a catalytic cysteine to serine. J Mol Biol 2014; 426:4018-4029. [PMID: 25451033 DOI: 10.1016/j.jmb.2014.10.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 10/15/2014] [Accepted: 10/26/2014] [Indexed: 11/24/2022]
Abstract
Inteins self-catalytically cleave out of precursor proteins while ligating the surrounding extein fragments with a native peptide bond. Much attention has been lavished on these molecular marvels with the hope of understanding and harnessing their chemistry for novel biochemical transformations including coupling peptides from synthetic or biological origins and controlling protein function. Despite an abundance of powerful applications, the use of inteins is still hampered by limitations in our understanding of their specificity (defined as flanking sequences that permit splicing) and the challenge of inserting inteins into target proteins. We examined the frequently used Nostoc punctiforme Npu DnaE intein after the C-extein cysteine nucleophile (Cys+1) was mutated to serine or threonine. Previous studies demonstrated reduced rates and/or splicing yields with the Npu DnaE intein after mutation of Cys+1 to Ser+1. In this study, genetic selection identified extein sequences with Ser+1 that enabled the Npu DnaE intein to splice with only a 5-fold reduction in rate compared to the wild-type Cys+1 intein and without mutation of the intein itself to activate Ser+1 as a nucleophile. Three different proteins spliced efficiently after insertion of the intein flanked by the selected sequences. We then used this selected specificity to achieve traceless splicing in a targeted enzyme at a location predicted by primary sequence similarity to only the selected C-extein sequence. This study highlights the latent catalytic potential of the Npu DnaE intein to splice with an alternative nucleophile and enables broader intein utility by increasing insertion site choices.
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Affiliation(s)
- Manoj Cheriyan
- New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Siu-Hong Chan
- New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Francine Perler
- New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA.
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