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Ji Y, Li J, Liang Y, Li L, Wang Y, Pi L, Xing P, Nomura CT, Chen S, Zhu C, Wang Q. Engineering the Tat-secretion pathway of Bacillus licheniformis for the secretion of cytoplasmic enzyme arginase. Appl Microbiol Biotechnol 2024; 108:89. [PMID: 38194145 DOI: 10.1007/s00253-023-12917-2] [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: 07/25/2023] [Revised: 10/06/2023] [Accepted: 10/16/2023] [Indexed: 01/10/2024]
Abstract
The industrial bacterium Bacillus licheniformis has long been used as a microbial factory for the production of enzymes due to its ability to secrete copious amounts of native extracellular proteins and its generally regarded as safe (GRAS) status. However, most attempts to use B. licheniformis to produce heterologous and cytoplasmic enzymes primarily via the general secretory (Sec) pathway have had limited success. The twin-arginine transport (Tat) pathway offers a promising alternative for the extracellular export of Sec-incompatible proteins because it transports full, correctly folded proteins. However, compared to the Sec pathway, the yields of the Tat pathway have historically been too low for commercial use. To improve the export efficiency of the Tat pathway, we identified the optimal Tat-dependent signal peptides and increased the abundance of the Tat translocases, the signal peptidase (SPase), and the intracellular chaperones. These strategic modifications significantly improved the Tat-dependent secretion of the cytoplasmic enzyme arginase into the culture medium using B. licheniformis. The extracellular enzymatic activity of arginase showed a 5.2-fold increase after these modifications. Moreover, compared to the start strain B. licheniformis 0F3, the production of extracellular GFP was improved by 3.8 times using the strategic modified strain B. licheniformis 0F13, and the extracellular enzymatic activity of SOX had a 1.3-fold increase using the strain B. licheniformis 0F14. This Tat-based production chassis has the potential for enhanced production of Sec-incompatible enzymes, therefore expanding the capability of B. licheniformis as an efficient cellular factory for the production of high-value proteins. KEY POINTS: • Systematic genetic modification of Tat-pathway in B. licheniformis. • Significant enhancement of the secretion capacity of Tat pathway for delivery the cytoplasmic enzyme arginase. • A new platform for efficient extracellular production of Sec-incompatible enzymes.
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Affiliation(s)
- Yi Ji
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Science, Hubei University, Wuhan, 430062, People's Republic of China
| | - Junliang Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Science, Hubei University, Wuhan, 430062, People's Republic of China
| | - Yonglin Liang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Science, Hubei University, Wuhan, 430062, People's Republic of China
| | - Liang Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Science, Hubei University, Wuhan, 430062, People's Republic of China
| | - Yajun Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Science, Hubei University, Wuhan, 430062, People's Republic of China
| | - Li Pi
- Wuhan Grand Hoyo Co., Ltd, Wuhan, 430075, People's Republic of China
| | - Panpan Xing
- Wuhan Grand Hoyo Co., Ltd, Wuhan, 430075, People's Republic of China
| | - Christopher T Nomura
- Department of Biological Sciences, University of Idaho, 875 Perimeter Drive, Moscow, ID, 83844, USA
| | - Shouwen Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Science, Hubei University, Wuhan, 430062, People's Republic of China
| | - Chengjun Zhu
- Wuhan Grand Hoyo Co., Ltd, Wuhan, 430075, People's Republic of China.
| | - Qin Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Science, Hubei University, Wuhan, 430062, People's Republic of China.
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Engineering Bacillus subtilis Cells as Factories: Enzyme Secretion and Value-added Chemical Production. BIOTECHNOL BIOPROC E 2020. [DOI: 10.1007/s12257-020-0104-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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3
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Prajapati B, Bernal-Cabas M, López-Álvarez M, Schaffer M, Bartel J, Rath H, Steil L, Becher D, Völker U, Mäder U, van Dijl JM. Double trouble: Bacillus depends on a functional Tat machinery to avoid severe oxidative stress and starvation upon entry into a NaCl-depleted environment. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118914. [PMID: 33245978 DOI: 10.1016/j.bbamcr.2020.118914] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 11/08/2020] [Accepted: 11/20/2020] [Indexed: 11/17/2022]
Abstract
The widely conserved twin-arginine translocases (Tat) allow the transport of fully folded cofactor-containing proteins across biological membranes. In doing so, these translocases serve different biological functions ranging from energy conversion to cell division. In the Gram-positive soil bacterium Bacillus subtilis, the Tat machinery is essential for effective growth in media lacking iron or NaCl. It was previously shown that this phenomenon relates to the Tat-dependent export of the heme-containing peroxidase EfeB, which converts Fe2+ to Fe3+ at the expense of hydrogen peroxide. However, the reasons why the majority of tat mutant bacteria perish upon dilution in NaCl-deprived medium and how, after several hours, a sub-population adapts to this condition was unknown. Here we show that, upon growth in the absence of NaCl, the bacteria face two major problems, namely severe oxidative stress at the membrane and starvation leading to death. The tat mutant cells can overcome these challenges if they are fed with arginine, which implies that severe arginine depletion is a major cause of death and resumed arginine synthesis permits their survival. Altogether, our findings show that the Tat system of B. subtilis is needed to preclude severe oxidative stress and starvation upon sudden drops in the environmental Na+ concentration as caused by flooding or rain.
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Affiliation(s)
- Bimal Prajapati
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, the Netherlands
| | - Margarita Bernal-Cabas
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, the Netherlands
| | - Marina López-Álvarez
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, the Netherlands
| | - Marc Schaffer
- University Medicine Greifswald, Interfaculty Institute of Genetics and Functional Genomics, Department of Functional Genomics, Greifswald, Germany
| | - Jürgen Bartel
- University of Greifswald, Institute of Microbiology, Department of Microbial Proteomics, Greifswald, Germany
| | - Hermann Rath
- University Medicine Greifswald, Interfaculty Institute of Genetics and Functional Genomics, Department of Functional Genomics, Greifswald, Germany
| | - Leif Steil
- University Medicine Greifswald, Interfaculty Institute of Genetics and Functional Genomics, Department of Functional Genomics, Greifswald, Germany
| | - Dörte Becher
- University of Greifswald, Institute of Microbiology, Department of Microbial Proteomics, Greifswald, Germany
| | - Uwe Völker
- University Medicine Greifswald, Interfaculty Institute of Genetics and Functional Genomics, Department of Functional Genomics, Greifswald, Germany
| | - Ulrike Mäder
- University Medicine Greifswald, Interfaculty Institute of Genetics and Functional Genomics, Department of Functional Genomics, Greifswald, Germany.
| | - Jan Maarten van Dijl
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, the Netherlands.
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Bernal-Cabas M, Miethke M, Antelo-Varela M, Aguilar Suárez R, Neef J, Schön L, Gabarrini G, Otto A, Becher D, Wolf D, van Dijl JM. Functional association of the stress-responsive LiaH protein and the minimal TatAyCy protein translocase in Bacillus subtilis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118719. [DOI: 10.1016/j.bbamcr.2020.118719] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 04/07/2020] [Accepted: 04/09/2020] [Indexed: 01/07/2023]
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Abstract
The Tat pathway for protein translocation across bacterial membranes stands out for its selective handling of fully folded cargo proteins. In this review, we provide a comprehensive summary of our current understanding of the different known Tat components, their assembly into different complexes, and their specific roles in the protein translocation process. In particular, this overview focuses on the Gram-negative bacterium Escherichia coli and the Gram-positive bacterium Bacillus subtilis. Using these organisms as examples, we discuss structural features of Tat complexes alongside mechanistic models that allow for the Tat pathway's unique protein proofreading and transport capabilities. Finally, we highlight recent advances in exploiting the Tat pathway for biotechnological benefit, the production of high-value pharmaceutical proteins.
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6
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Abstract
The twin-arginine protein translocation (Tat) system has been characterized in bacteria, archaea and the chloroplast thylakoidal membrane. This system is distinct from other protein transport systems with respect to two key features. Firstly, it accepts cargo proteins with an N-terminal signal peptide that carries the canonical twin-arginine motif, which is essential for transport. Second, the Tat system only accepts and translocates fully folded cargo proteins across the respective membrane. Here, we review the core essential features of folded protein transport via the bacterial Tat system, using the three-component TatABC system of Escherichia coli and the two-component TatAC systems of Bacillus subtilis as the main examples. In particular, we address features of twin-arginine signal peptides, the essential Tat components and how they assemble into different complexes, mechanistic features and energetics of Tat-dependent protein translocation, cytoplasmic chaperoning of Tat cargo proteins, and the remarkable proofreading capabilities of the Tat system. In doing so, we present the current state of our understanding of Tat-dependent protein translocation across biological membranes, which may serve as a lead for future investigations.
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Affiliation(s)
- Kelly M. Frain
- The School of Biosciences, University of Kent, Canterbury, CT2 7NZ UK
| | - Colin Robinson
- The School of Biosciences, University of Kent, Canterbury, CT2 7NZ UK
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University Medical Center Groningen, University of Groningen (UMCG), Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen, The Netherlands
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Ghosh D, Boral D, Vankudoth KR, Ramasamy S. Analysis of haloarchaeal twin-arginine translocase pathway reveals the diversity of the machineries. Heliyon 2019; 5:e01587. [PMID: 31193317 PMCID: PMC6525301 DOI: 10.1016/j.heliyon.2019.e01587] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 03/23/2019] [Accepted: 04/24/2019] [Indexed: 01/10/2023] Open
Abstract
The twin-arginine translocase (Tat) pathway transports folded proteins across the plasma membrane and plays a critical role in protein transport in haloarchaea. Computational analysis and previous experimental evidence suggested that the Tat pathway transports almost the entire secretome in haloarchaea. The TatC, receptor component of this pathway shows greater variation in membrane topology in haloarchaea than in other organisms. The presence of a unique fourteen-transmembrane TatC homolog (TatCt) in haloarchaea, over and above the expected TatC topological variants, indicates a strong correlation between the additional homologs and the large number of substrates transported via the haloarchaeal Tat pathway. Various combinations of TatC homologs with different topologies—TatCo, TatCt, TatCn, and TatCx have been observed in haloarchaea. In this report, on the basis of these combinations we have segregated all haloarchaeal Tat substrates into two groups. The first group consists of substrates that are transported by TatCt alone, whereas the second group consists of substrates that are transported by the other TatC homologs (TatCo, TatCn, and TatCx). The various haloarchaea TatA components also shows the possible segregation towards the substrates. We have also identified the possible homologs for Tat substrate chaperones, which act as a quality-control mechanism for proper protein folding. Further sequence analysis implies that the two TatC domains of TatCt complement each other's functionally. Substrate analysis also revealed subtle differences between the substrates being transported by various homologs: further experimental analysis is therefore required for better understanding of the complexities of the haloarchaeal Tat pathway.
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Affiliation(s)
- Deepanjan Ghosh
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune 411008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad- 201002, India
| | - Debjyoti Boral
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune 411008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad- 201002, India
| | - Koteswara Rao Vankudoth
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune 411008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad- 201002, India
| | - Sureshkumar Ramasamy
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune 411008, India
- Corresponding author.
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Ni J, Xu L, Li W, Zheng C, Wu L. Targeted metabolomics for serum amino acids and acylcarnitines in patients with lung cancer. Exp Ther Med 2019; 18:188-198. [PMID: 31258653 PMCID: PMC6566041 DOI: 10.3892/etm.2019.7533] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Accepted: 12/06/2018] [Indexed: 12/13/2022] Open
Abstract
Lung cancer is one of the most prevalent types of cancer, but accurate diagnosis remains a challenge. The aim of the present study was to create a model using amino acids and acylcarnitines for lung cancer screening. Serum samples were obtained from two groups of patients with lung cancer recruited in 2015 (including 40 patients and 100 matched controls) and 2017 (including 17 patients and 30 matched controls). Using a metabolomics method, 21 metabolites (13 types of amino acids and 8 types of acylcarnitines) were measured using liquid chromatography-tandem mass spectrometry. Data (from the 2015 and 2017 data sets) were analysed using a Mann-Whitney U test, Student's t-test, Welch's F test, receiver-operator characteristic curve or logistic regression in order to investigate the potential biomarkers. Six metabolites (glycine, valine, methionine, citrulline, arginine and C16-carnitine) were indicated to be involved in distinguishing patients with lung cancer from healthy controls. The six discriminating metabolites from the 2017 data set were further analysed using Partial least squares-discriminant analysis (PLS-DA). The PLS-DA model was verified using Spearman's correlation analysis and receiver operating characteristic curve analysis. These results demonstrated that the PLS-DA model using the six metabolites (glycine, valine, methionine, citrulline, arginine and C16-carnitine) had a strong ability to identify lung cancer. Therefore, the PLS-DA model using glycine, valine, methionine, citrulline, arginine and C16-carnitine may become a novel screening tool in patients with lung cancer.
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Affiliation(s)
- Junjun Ni
- Department of Medicinal Chemistry and Natural Medicine Chemistry, College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China.,Beijing Harmony Health Medical Diagnostics Co., Ltd., Beijing 101111, P.R. China
| | - Li Xu
- Beijing Harmony Health Medical Diagnostics Co., Ltd., Beijing 101111, P.R. China
| | - Wei Li
- Beijing Harmony Health Medical Diagnostics Co., Ltd., Beijing 101111, P.R. China
| | - Chunmei Zheng
- Beijing Harmony Health Medical Diagnostics Co., Ltd., Beijing 101111, P.R. China
| | - Lijun Wu
- Department of Medicinal Chemistry and Natural Medicine Chemistry, College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
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Huang X, Cao L, Qin Z, Li S, Kong W, Liu Y. Tat-Independent Secretion of Polyethylene Terephthalate Hydrolase PETase in Bacillus subtilis 168 Mediated by Its Native Signal Peptide. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:13217-13227. [PMID: 30465427 DOI: 10.1021/acs.jafc.8b05038] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Widespread utilization of polyethylene terephthalate (PET) has caused critical environmental pollution. The enzymatic degradation of PET is a promising solution to this problem. In this study, PETase, which exhibits much higher PET-hydrolytic activity than other enzymes, was successfully secreted into extracellular milieu from Bacillus subtilis 168 under the direction of its native signal peptide (named SPPETase). SPPETase is predicted to be a twin-arginine signal peptide. Intriguingly, inactivation of twin-arginine translocation (Tat) complexes improved the secretion amount by 3.8-fold, indicating that PETase was exported via Tat-independent pathway. To the best of our knowledge, this is the first report on the improvement of Tat-independent secretion by inactivating Tat components of B. subtilis 168 in LB medium. Furthermore, PET film degradation assay showed that the secreted PETase was fully active. This study paves the first step to construct an efficient engineered strain for PET degradation.
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Affiliation(s)
- Xin Huang
- School of Life Sciences, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, National Engineering Center for Marine Biotechnology of South China Sea , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
| | - Lichuang Cao
- School of Life Sciences, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, National Engineering Center for Marine Biotechnology of South China Sea , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
| | - Zongmin Qin
- School of Life Sciences, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, National Engineering Center for Marine Biotechnology of South China Sea , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
| | - Shuifeng Li
- School of Life Sciences, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, National Engineering Center for Marine Biotechnology of South China Sea , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
| | - Wei Kong
- School of Life Sciences, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, National Engineering Center for Marine Biotechnology of South China Sea , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
| | - Yuhuan Liu
- School of Life Sciences, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, National Engineering Center for Marine Biotechnology of South China Sea , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
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10
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Gimenez MR, Chandra G, Van Overvelt P, Voulhoux R, Bleves S, Ize B. Genome wide identification and experimental validation of Pseudomonas aeruginosa Tat substrates. Sci Rep 2018; 8:11950. [PMID: 30093651 PMCID: PMC6085387 DOI: 10.1038/s41598-018-30393-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 07/30/2018] [Indexed: 11/13/2022] Open
Abstract
In bacteria, the twin-arginine translocation (Tat) pathway allows the export of folded proteins through the inner membrane. Proteins targeted to this system are synthesized with N-terminal signal peptides bearing a conserved twin-arginine motif. The Tat pathway is critical for many bacterial processes including pathogenesis and virulence. However, the full set of Tat substrates is unknown in many bacteria, and the reliability of in silico prediction methods largely uncertain. In this work, we performed a combination of in silico analysis and experimental validation to identify a core set of Tat substrates in the opportunistic pathogen Pseudomonas aeruginosa. In silico analysis predicted 44 putative Tat signal peptides in the P. aeruginosa PA14 proteome. We developed an improved amidase-based Tat reporter assay to show that 33 of these are real Tat signal peptides. In addition, in silico analysis of the full translated genome revealed a Tat candidate with a missassigned start codon. We showed that it is a new periplasmic protein in P. aeruginosa. Altogether we discovered and validated 34 Tat substrates. These show little overlap with Escherichia coli Tat substrates, and functional analysis points to a general role for the P. aeruginosa Tat system in the colonization of environmental niches and pathogenicity.
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Affiliation(s)
- Maxime Rémi Gimenez
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille Univ., 31 Chemin Joseph Aiguier, CS 70071, 13402 Marseille cedex 09, France
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Perrine Van Overvelt
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille Univ., 31 Chemin Joseph Aiguier, CS 70071, 13402 Marseille cedex 09, France
| | - Romé Voulhoux
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille Univ., 31 Chemin Joseph Aiguier, CS 70071, 13402 Marseille cedex 09, France
| | - Sophie Bleves
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille Univ., 31 Chemin Joseph Aiguier, CS 70071, 13402 Marseille cedex 09, France
| | - Bérengère Ize
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM-UMR7255), Institut de Microbiologie de la Méditerranée, CNRS and Aix-Marseille Univ., 31 Chemin Joseph Aiguier, CS 70071, 13402 Marseille cedex 09, France.
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11
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Hohmann HP, van Dijl JM, Krishnappa L, Prágai Z. Host Organisms:Bacillus subtilis. Ind Biotechnol (New Rochelle N Y) 2016. [DOI: 10.1002/9783527807796.ch7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Hans-Peter Hohmann
- Nutrition Innovation Center R&D Biotechnology; DSM Nutritional Products Ltd; Wurmisweg 576 CH-4303 Kaiseraugst Switzerland
| | - Jan M. van Dijl
- University of Groningen, University Medical Center Groningen; Department of Medical Microbiology; Hanzeplein 1 9700 RB Groningen The Netherlands
| | - Laxmi Krishnappa
- University of Groningen, University Medical Center Groningen; Department of Medical Microbiology; Hanzeplein 1 9700 RB Groningen The Netherlands
| | - Zoltán Prágai
- Nutrition Innovation Center R&D Biotechnology; DSM Nutritional Products Ltd; Wurmisweg 576 CH-4303 Kaiseraugst Switzerland
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12
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Secretory expression of a heterologous protein, Aiio-AIO6BS, in Bacillus subtilis via a non-classical secretion pathway. Biochem Biophys Res Commun 2016; 478:881-6. [DOI: 10.1016/j.bbrc.2016.08.045] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 08/08/2016] [Indexed: 12/27/2022]
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13
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Ren GH, Cao LC, Kong W, Wang ZJ, Liu YH. Efficient Secretion of the β-Galactosidase Bgal1-3 via both Tat-Dependent and Tat-Independent Pathways in Bacillus subtilis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:5708-5716. [PMID: 27380825 DOI: 10.1021/acs.jafc.6b01735] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this study, the twin-arginine (Tat) signal peptide PhoD was used to direct the secretion of the β-galactosidase Bgal1-3 into the growth medium of an engineered strain of Bacillus subtilis 168. After 24 h of cultivation, the extracellular activity reached 1.15 U/mL, representing 78% of the total activity. Bgal1-3 was exported via both Tat-dependent and Tat-independent pathways. To improve the secretion amounts, two more copies of the target gene were inserted into the designated loci on the chromosome, further improving the extracellular enzymatic activity to 2.15 U/mL. The engineered strain with three copies of bgal1-3 was genetically stable after 150 generations. To the best of our knowledge, this is the first report on the functional secretion of a heterologous protein via both Tat-dependent and Tat-independent pathways mediated by a Tat signal peptide in B. subtilis. Furthermore, this study provides us with a markerless engineered strain for the production of β-galactosidase.
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Affiliation(s)
- Guang-Hui Ren
- School of Life Sciences and South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Sun Yat-sen University , Guangzhou 510275, P. R. China
| | - Li-Chuang Cao
- School of Life Sciences and South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Sun Yat-sen University , Guangzhou 510275, P. R. China
| | - Wei Kong
- School of Life Sciences and South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Sun Yat-sen University , Guangzhou 510275, P. R. China
| | - Zhi-Jun Wang
- School of Life Sciences and South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Sun Yat-sen University , Guangzhou 510275, P. R. China
| | - Yu-Huan Liu
- School of Life Sciences and South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Sun Yat-sen University , Guangzhou 510275, P. R. China
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14
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Contribution of the Twin Arginine Translocation system to the exoproteome of Pseudomonas aeruginosa. Sci Rep 2016; 6:27675. [PMID: 27279369 PMCID: PMC4899797 DOI: 10.1038/srep27675] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 05/23/2016] [Indexed: 01/24/2023] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa uses secretion systems to deliver exoproteins into the environment. These exoproteins contribute to bacterial survival, adaptation, and virulence. The Twin arginine translocation (Tat) export system enables the export of folded proteins into the periplasm, some of which can then be further secreted outside the cell. However, the full range of proteins that are conveyed by Tat is unknown, despite the importance of Tat for the adaptability and full virulence of P. aeruginosa. In this work, we explored the P. aeruginosa Tat-dependent exoproteome under phosphate starvation by two-dimensional gel analysis. We identified the major secreted proteins and new Tat-dependent exoproteins. These exoproteins were further analyzed by a combination of in silico analysis, regulation studies, and protein localization. Altogether we reveal that the absence of the Tat system significantly affects the composition of the exoproteome by impairing protein export and affecting gene expression. Notably we discovered three new Tat exoproteins and one novel type II secretion substrate. Our data also allowed the identification of two new start codons highlighting the importance of protein annotation for subcellular predictions. The new exoproteins that we identify may play a significant role in P. aeruginosa pathogenesis, host interaction and niche adaptation.
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15
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Abstract
Twin-arginine protein translocation systems (Tat) translocate fully folded and co-factor-containing proteins across biological membranes. In this review, we focus on the Tat pathway of Gram-positive bacteria. The minimal Tat pathway is composed of two components, namely a TatA and TatC pair, which are often complemented with additional TatA-like proteins. We provide overviews of our current understanding of Tat pathway composition and mechanistic aspects related to Tat-dependent cargo protein translocation. This includes Tat pathway flexibility, requirements for the correct folding and incorporation of co-factors in cargo proteins and the functions of known cargo proteins. Tat pathways of several Gram-positive bacteria are discussed in detail, with emphasis on the Tat pathway of Bacillus subtilis. We discuss both shared and unique features of the different Gram-positive bacterial Tat pathways. Lastly, we highlight topics for future research on Tat, including the development of this protein transport pathway for the biotechnological secretion of high-value proteins and its potential applicability as an antimicrobial drug target in pathogens.
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Affiliation(s)
- Vivianne J Goosens
- MRC Centre for Molecular Bacteriology and Infection, Section of Microbiology, Imperial College London, London, SW7 2AZ, UK
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, 9700, RB, Groningen, The Netherlands.
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A Tat ménage à trois — The role of Bacillus subtilis TatAc in twin-arginine protein translocation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:2745-53. [DOI: 10.1016/j.bbamcr.2015.07.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/28/2015] [Accepted: 07/30/2015] [Indexed: 11/19/2022]
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17
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Optimization of the secretion pathway for heterologous proteins in Bacillus subtilis. BIOTECHNOL BIOPROC E 2015. [DOI: 10.1007/s12257-014-0843-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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18
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Handtke S, Volland S, Methling K, Albrecht D, Becher D, Nehls J, Bongaerts J, Maurer KH, Lalk M, Liesegang H, Voigt B, Daniel R, Hecker M. Cell physiology of the biotechnological relevant bacterium Bacillus pumilus-an omics-based approach. J Biotechnol 2014; 192 Pt A:204-14. [PMID: 25281541 DOI: 10.1016/j.jbiotec.2014.08.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 08/15/2014] [Accepted: 08/22/2014] [Indexed: 12/18/2022]
Abstract
Members of the species Bacillus pumilus get more and more in focus of the biotechnological industry as potential new production strains. Based on exoproteome analysis, B. pumilus strain Jo2, possessing a high secretion capability, was chosen for an omics-based investigation. The proteome and metabolome of B. pumilus cells growing either in minimal or complex medium was analyzed. In total, 1542 proteins were identified in growing B. pumilus cells, among them 1182 cytosolic proteins, 297 membrane and lipoproteins and 63 secreted proteins. This accounts for about 43% of the 3616 proteins encoded in the B. pumilus Jo2 genome sequence. By using GC-MS, IP-LC/MS and H NMR methods numerous metabolites were analyzed and assigned to reconstructed metabolic pathways. In the genome sequence a functional secretion system including the components of the Sec- and Tat-secretion machinery was found. Analysis of the exoproteome revealed secretion of about 70 proteins with predicted secretion signals. In addition, selected production-relevant genome features such as restriction modification systems and NRPS clusters of B. pumilus Jo2 are discussed.
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Affiliation(s)
- Stefan Handtke
- Institute for Microbiology, Ernst-Moritz-Arndt University, Greifswald, Germany.
| | - Sonja Volland
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University Göttingen, Göttingen, Germany.
| | - Karen Methling
- Institute of Biochemistry, Ernst-Moritz-Arndt University, Greifswald, Germany.
| | - Dirk Albrecht
- Institute for Microbiology, Ernst-Moritz-Arndt University, Greifswald, Germany.
| | - Dörte Becher
- Institute for Microbiology, Ernst-Moritz-Arndt University, Greifswald, Germany.
| | - Jenny Nehls
- Institute of Biochemistry, Ernst-Moritz-Arndt University, Greifswald, Germany.
| | - Johannes Bongaerts
- Department of Chemistry and Biotechnology, Aachen University of Applied Sciences, Heinrich-Mußmannstr. 1, 52428 Jülich, Germany.
| | | | - Michael Lalk
- Institute of Biochemistry, Ernst-Moritz-Arndt University, Greifswald, Germany.
| | - Heiko Liesegang
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University Göttingen, Göttingen, Germany.
| | - Birgit Voigt
- Institute for Microbiology, Ernst-Moritz-Arndt University, Greifswald, Germany.
| | - Rolf Daniel
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University Göttingen, Göttingen, Germany.
| | - Michael Hecker
- Institute for Microbiology, Ernst-Moritz-Arndt University, Greifswald, Germany.
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19
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Rodriguez F, Lillington J, Johnson S, Timmel CR, Lea SM, Berks BC. Crystal structure of the Bacillus subtilis phosphodiesterase PhoD reveals an iron and calcium-containing active site. J Biol Chem 2014; 289:30889-99. [PMID: 25217636 PMCID: PMC4223295 DOI: 10.1074/jbc.m114.604892] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
The PhoD family of extra-cytoplasmic phosphodiesterases are among the most commonly occurring bacterial phosphatases. The exemplars for this family are the PhoD protein of Bacillus subtilis and the phospholipase D of Streptomyces chromofuscus. We present the crystal structure of B. subtilis PhoD. PhoD is most closely related to purple acid phosphatases (PAPs) with both types of enzyme containing a tyrosinate-ligated Fe3+ ion. However, the PhoD active site diverges from that found in PAPs and uses two Ca2+ ions instead of the single extra Fe2+, Mn2+, or Zn2+ ion present in PAPs. The PhoD crystals contain a phosphate molecule that coordinates all three active site metal ions and that is proposed to represent a product complex. A C-terminal helix lies over the active site and controls access to the catalytic center. The structure of PhoD defines a new phosphatase active site architecture based on Fe3+ and Ca2+ ions.
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Affiliation(s)
- Fernanda Rodriguez
- From the Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU
| | - James Lillington
- the Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, and the Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Steven Johnson
- the Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, and
| | - Christiane R Timmel
- the Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Susan M Lea
- the Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, and
| | - Ben C Berks
- From the Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU,
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20
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Patel R, Vasilev C, Beck D, Monteferrante CG, van Dijl JM, Hunter CN, Smith C, Robinson C. A mutation leading to super-assembly of twin-arginine translocase (Tat) protein complexes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:1978-86. [PMID: 24875903 DOI: 10.1016/j.bbamcr.2014.05.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/16/2014] [Accepted: 05/19/2014] [Indexed: 10/25/2022]
Abstract
The Tat system transports folded proteins across the bacterial plasma membrane. The mechanism is believed to involve coalescence of a TatC-containing unit with a separate TatA complex, but the full translocation complex has never been visualised and the assembly process is poorly defined. We report the analysis of the Bacillus subtilis TatAyCy system, which occurs as separate TatAyCy and TatAy complexes at steady state, using single-particle electron microscopy (EM) and advanced atomic force microscopy (AFM) approaches. We show that a P2A mutation in the TatAy subunit leads to apparent super-assembly of Tat complexes. Purification of TatCy-containing complexes leads to a large increase in the TatA:TatC ratio, suggesting that TatAy(P2A) complexes may have attached to the TatAyCy complex. EM and AFM analyses show that the wild-type TatAyCy complex purifies as roughly spherical complexes of 9-16nm diameter, whereas the P2A mutation leads to accumulation of large (up to 500nm long) fibrils that are chains of numerous complexes. Time lapsed AFM imaging, recorded on fibrils under liquid, shows that they adopt a variety of tightly curved conformations, with radii of curvature of 10-12nm comparable to the size of single TatAy(P2A) complexes. The combined data indicate that the mutation leads to super-assembly of TatAy(P2A) complexes and we propose that an individual TatAy(P2A) complex assembles initially with a TatAy(P2A)Cy complex, after which further TatAy(P2A) complexes attach to each other. The data further suggest that the N-terminal extracytoplasmic domain of TatAy plays an essential role in Tat complex interactions.
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Affiliation(s)
- Roshani Patel
- School of Life Sciences, Gibbet Hill Campus, The University of Warwick, Coventry CV4 7AL, UK
| | - Cvetelin Vasilev
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Daniel Beck
- School of Life Sciences, Gibbet Hill Campus, The University of Warwick, Coventry CV4 7AL, UK
| | - Carmine G Monteferrante
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Corinne Smith
- School of Life Sciences, Gibbet Hill Campus, The University of Warwick, Coventry CV4 7AL, UK
| | - Colin Robinson
- Centre for Molecular Processing, School of Biosciences, University of Kent, Canterbury CT2 7NJ, UK.
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21
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Signal peptide of cellulase. Appl Microbiol Biotechnol 2014; 98:5329-62. [DOI: 10.1007/s00253-014-5742-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 03/28/2014] [Accepted: 03/30/2014] [Indexed: 12/24/2022]
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22
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Liu R, Zuo Z, Xu Y, Song C, Jiang H, Qiao C, Xu P, Zhou Q, Yang C. Twin-arginine signal peptide of Bacillus subtilis YwbN can direct Tat-dependent secretion of methyl parathion hydrolase. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:2913-2918. [PMID: 24620988 DOI: 10.1021/jf405694n] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The twin-arginine translocation (Tat) pathway exports folded proteins across the cytoplasmic membranes of bacteria and archaea. Two parallel Tat pathways (TatAdCd and TatAyCy systems) with distinct substrate specificities have previously been discovered in Bacillus subtilis. In this study, to secrete methyl parathion hydrolase (MPH) into the growth medium, the twin-arginine signal peptide of B. subtilis YwbN was used to target MPH to the Tat pathway of B. subtilis. Western blot analysis and MPH assays demonstrated that active MPH was secreted into the culture supernatant of wild-type cells. No MPH secretion occurred in a total-tat2 mutant, indicating that the observed export in wild-type cells was mediated exclusively by the Tat pathway. Export was fully blocked in a tatAyCy mutant. In contrast, the tatAdCd mutant was still capable of secreting MPH. These results indicated that the MPH secretion directed by the YwbN signal peptide was specifically mediated by the TatAyCy system. The N-terminal sequence of secreted MPH was determined as AAPQVR, demonstrating that the YwbN signal peptide had been processed correctly. This is the first report of functional secretion of a heterologous protein via the B. subtilis TatAyCy system. This study highlights the potential of the TatAyCy system to be used for secretion of other heterologous proteins in B. subtilis.
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Affiliation(s)
- Ruihua Liu
- College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, §Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, Department of Microbiology, College of Life Sciences, and ¶Key Laboratory of Pollution Processes and Environmental Criteria for Ministry of Education, College of Environmental Science and Engineering, Nankai University , Tianjin 300071, People's Republic of China
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23
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Goosens VJ, Monteferrante CG, van Dijl JM. Co-factor insertion and disulfide bond requirements for twin-arginine translocase-dependent export of the Bacillus subtilis Rieske protein QcrA. J Biol Chem 2014; 289:13124-31. [PMID: 24652282 DOI: 10.1074/jbc.m113.529677] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The twin-arginine translocation (Tat) pathway can transport folded and co-factor-containing cargo proteins over bacterial cytoplasmic membranes. Functional Tat machinery components, a folded state of the cargo protein and correct co-factor insertion in the cargo protein are generally considered as prerequisites for successful translocation. The present studies were aimed at a dissection of these requirements with regard to the Rieske iron-sulfur protein QcrA of Bacillus subtilis. Notably, QcrA is a component of the cytochrome bc1 complex, which is conserved from bacteria to man. Single amino acid substitutions were introduced into the Rieske domain of QcrA to prevent either co-factor binding or disulfide bond formation. Both types of mutations precluded QcrA translocation. Importantly, a proofreading hierarchy was uncovered, where a QcrA mutant defective in disulfide bonding was quickly degraded, whereas mutant QcrA proteins defective in co-factor binding accumulated in the cytoplasm and membrane. Altogether, these are the first studies on Tat-dependent protein translocation where both oxidative folding and co-factor attachment have been addressed in a single native molecule.
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Affiliation(s)
- Vivianne J Goosens
- From the Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P. O. Box 30001, 9700 RB, Groningen, The Netherlands
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24
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The canonical twin-arginine translocase components are not required for secretion of folded green fluorescent protein from the ancestral strain of Bacillus subtilis. Appl Environ Microbiol 2014; 80:3219-32. [PMID: 24632256 DOI: 10.1128/aem.00335-14] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cellular processes, such as the digestion of macromolecules, phosphate acquisition, and cell motility, require bacterial secretion systems. In Bacillus subtilis, the predominant protein export pathways are Sec (generalized secretory pathway) and Tat (twin-arginine translocase). Unlike Sec, which secretes unfolded proteins, the Tat machinery secretes fully folded proteins across the plasma membrane and into the medium. Proteins are directed for Tat-dependent export by N-terminal signal peptides that contain a conserved twin-arginine motif. Thus, utilizing the Tat secretion system by fusing a Tat signal peptide is an attractive strategy for the production and export of heterologous proteins. As a proof of concept, we expressed green fluorescent protein (GFP) fused to the PhoD Tat signal peptide in the laboratory and ancestral strains of B. subtilis. Secretion of the Tat-GFP construct, as well as secretion of proteins in general, was substantially increased in the ancestral strain. Furthermore, our results show that secreted, fluorescent GFP could be purified directly from the extracellular medium. Nonetheless, export was not dependent on the known Tat secretion components or the signal peptide twin-arginine motif. We propose that the ancestral strain contains additional Tat components and/or secretion regulators that were abrogated following domestication.
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25
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26
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Patel R, Smith SM, Robinson C. Protein transport by the bacterial Tat pathway. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:1620-8. [PMID: 24583120 DOI: 10.1016/j.bbamcr.2014.02.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 02/10/2014] [Accepted: 02/15/2014] [Indexed: 10/25/2022]
Abstract
The twin-arginine translocation (Tat) system accomplishes the remarkable feat of translocating large - even dimeric - proteins across tightly sealed energy-transducing membranes. All of the available evidence indicates that it is unique in terms of both structure and mechanism; however its very nature has hindered efforts to probe the core translocation events. At the heart of the problem is the fact that two large sub-complexes are believed to coalesce to form the active translocon, and 'capturing' this translocation event has been too difficult. Nevertheless, studies on the individual components have come a long way in recent years, and structural studies have reached the point where educated guesses can be made concerning the most interesting aspects of Tat. In this article we review these studies and the emerging ideas in this field. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey.
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Affiliation(s)
- Roshani Patel
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Sarah M Smith
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Colin Robinson
- Centre for Molecular Processing, School of Biosciences, University of Kent, Canterbury CT2 7NJ, United Kingdom.
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27
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Simone D, Bay DC, Leach T, Turner RJ. Diversity and evolution of bacterial twin arginine translocase protein, TatC, reveals a protein secretion system that is evolving to fit its environmental niche. PLoS One 2013; 8:e78742. [PMID: 24236045 PMCID: PMC3827258 DOI: 10.1371/journal.pone.0078742] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 09/20/2013] [Indexed: 11/18/2022] Open
Abstract
Background The twin-arginine translocation (Tat) protein export system enables the transport of fully folded proteins across a membrane. This system is composed of two integral membrane proteins belonging to TatA and TatC protein families and in some systems a third component, TatB, a homolog of TatA. TatC participates in substrate protein recognition through its interaction with a twin arginine leader peptide sequence. Methodology/Principal Findings The aim of this study was to explore TatC diversity, evolution and sequence conservation in bacteria to identify how TatC is evolving and diversifying in various bacterial phyla. Surveying bacterial genomes revealed that 77% of all species possess one or more tatC loci and half of these classes possessed only tatC and tatA genes. Phylogenetic analysis of diverse TatC homologues showed that they were primarily inherited but identified a small subset of taxonomically unrelated bacteria that exhibited evidence supporting lateral gene transfer within an ecological niche. Examination of bacilli tatCd/tatCy isoform operons identified a number of known and potentially new Tat substrate genes based on their frequent association to tatC loci. Evolutionary analysis of these Bacilli isoforms determined that TatCy was the progenitor of TatCd. A bacterial TatC consensus sequence was determined and highlighted conserved and variable regions within a three dimensional model of the Escherichia coli TatC protein. Comparative analysis between the TatC consensus sequence and Bacilli TatCd/y isoform consensus sequences revealed unique sites that may contribute to isoform substrate specificity or make TatA specific contacts. Synonymous to non-synonymous nucleotide substitution analyses of bacterial tatC homologues determined that tatC sequence variation differs dramatically between various classes and suggests TatC specialization in these species. Conclusions/Significance TatC proteins appear to be diversifying within particular bacterial classes and its specialization may be driven by the substrates it transports and the environment of its host.
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Affiliation(s)
- Domenico Simone
- Institute of Biomembranes and Bioenergetics, National Research Council, Bari, Bari, Italy
| | - Denice C. Bay
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Thorin Leach
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Raymond J. Turner
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
- * E-mail:
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28
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Goosens VJ, Monteferrante CG, van Dijl JM. The Tat system of Gram-positive bacteria. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1843:1698-706. [PMID: 24140208 DOI: 10.1016/j.bbamcr.2013.10.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Revised: 10/08/2013] [Accepted: 10/08/2013] [Indexed: 10/26/2022]
Abstract
The twin-arginine protein translocation (Tat) system has a unique ability to translocate folded and co-factor-containing proteins across lipid bilayers. The Tat pathway is present in bacteria, archaea and in the thylakoid membranes of chloroplasts and, depending on the organism and environmental conditions, it can be deemed important for cell survival, virulence or bioproduction. This review provides an overview of the current understanding of the Tat system with specific focus on Gram-positive bacteria. The 'universal minimal Tat system' is composed of a TatA and a TatC protein. However, this pathway is more commonly composed of two TatA-like proteins and one TatC protein. Often the TatA-like proteins have diverged to have two different functions and, in this case, the second TatA-like protein is usually referred to as TatB. The correct folding and/or incorporation of co-factors are requirements for translocation, and the known quality control mechanisms are examined in this review. A number of examples of crosstalk between the Tat system and other protein transport systems, such as the Sec-YidC translocon and signal peptidases or sheddases are also discussed. Further, an overview of specific Gram-positive bacterial Tat systems found in monoderm and diderm species is detailed. Altogether, this review highlights the unique features of Gram-positive bacterial Tat systems and pinpoints key questions that remain to be addressed in future research. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey.
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Affiliation(s)
- Vivianne J Goosens
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen, The Netherlands
| | - Carmine G Monteferrante
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen, The Netherlands
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen, The Netherlands.
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Lippolis R, Siciliano RA, Mazzeo MF, Abbrescia A, Gnoni A, Sardanelli AM, Papa S. Comparative secretome analysis of four isogenic Bacillus clausii probiotic strains. Proteome Sci 2013; 11:28. [PMID: 23816335 PMCID: PMC3716886 DOI: 10.1186/1477-5956-11-28] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 06/07/2013] [Indexed: 12/24/2022] Open
Abstract
Background The spore-bearing alkaliphilic Bacillus species constitute a large, heterogeneous group of microorganisms, important for their ability to produce enzymes, antibodies and metabolites of potential medical use. Some Bacillus species are currently being used for manufacturing probiotic products consisting of bacterial spores, exhibiting specific features (colonization, immune-stimulation and antimicrobial activity) that can account for their claimed probiotic properties. In the present work a comparative proteomic study was performed aimed at characterizing the secretome of four closely related isogenic O/C, SIN, N/R and T B. clausii strains, already marketed in a pharmaceutical mixture as probiotics. Results Proteomic analyses revealed a high degree of concordance among the four secretomes, although some proteins exhibited considerable variations in their expression level in the four strains. Among these, some proteins with documented activity in the interaction with host cells were identified, such as the glycolytic enzyme enolase, with a putative plasminogen-binding activity, GroEL, a molecular chaperone shown to be able to bind to mucin, and flagellin protein, a structural flagella protein and a putative immunomodulation agent. Conclusion This study shows, for the first time, differences in the secretome of the OC, SIN, NR and T B. clausii strains. These differences indicate that specific secretome features characterize each of the four strains despite their genotypic similarity. This could confer to the B. clausii strains specific probiotic functions associated with the differentially expressed proteins and indicate that they can cooperate as probiotics as the secretome components of each strain could contribute to the overall activity of a mixed probiotic preparation.
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Affiliation(s)
- Rosa Lippolis
- Institute of Biomembranes and Bioenergetics, Italian National Research Council (CNR), Via Amendola 165/A, Bari, Italy.
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Ren C, Patel R, Robinson C. Exclusively membrane-inserted state of an uncleavable Tat precursor protein suggests lateral transfer into the bilayer from the translocon. FEBS J 2013; 280:3354-64. [PMID: 23647663 DOI: 10.1111/febs.12327] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Revised: 02/28/2013] [Accepted: 04/04/2013] [Indexed: 11/26/2022]
Abstract
In bacteria, the export of proteins by the twin-arginine translocase (Tat) pathway is directed by cleavable N-terminal signal peptides. We studied the relationship between transport and maturation using a substrate, YedY, that contains an Ala > Leu substitution at the -1 position of the signal peptide. This blocks maturation and leads to the accumulation of a membrane-bound precursor form with the mature domain exposed to the periplasm. Its accumulation does not block transport of other Tat substrates, indicating that exit from the translocation channel has taken place, and the precursor protein is fir mLy integrated into the membrane bilayer. The membrane-integrated nature of the precursor, and complete absence of precursor protein in the periplasm, strongly suggest that the precursor has undergone lateral transfer into the bilayer during translocation. We propose that subsequent proteolytic processing releases the mature protein into the periplasm. A delay in processing results in an inhibition of cell growth, emphasizing a requirement for efficient maturation of Tat substrates.
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Affiliation(s)
- Chao Ren
- School of Life Sciences, University of Warwick, Coventry, UK
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31
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Ramasamy S, Abrol R, Suloway CJ, Clemons WM. The glove-like structure of the conserved membrane protein TatC provides insight into signal sequence recognition in twin-arginine translocation. Structure 2013; 21:777-88. [PMID: 23583035 PMCID: PMC3653977 DOI: 10.1016/j.str.2013.03.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 02/14/2013] [Accepted: 03/07/2013] [Indexed: 11/23/2022]
Abstract
In bacteria, two signal-sequence-dependent secretion pathways translocate proteins across the cytoplasmic membrane. Although the mechanism of the ubiquitous general secretory pathway is becoming well understood, that of the twin-arginine translocation pathway, responsible for translocation of folded proteins across the bilayer, is more mysterious. TatC, the largest and most conserved of three integral membrane components, provides the initial binding site of the signal sequence prior to pore assembly. Here, we present two crystal structures of TatC from the thermophilic bacteria Aquifex aeolicus at 4.0 Å and 6.8 Å resolution. The membrane architecture of TatC includes a glove-shaped structure with a lipid-exposed pocket predicted by molecular dynamics to distort the membrane. Correlating the biochemical literature to these results suggests that the signal sequence binds in this pocket, leading to structural changes that facilitate higher order assemblies.
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Affiliation(s)
| | - Ravinder Abrol
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Christian J.M. Suloway
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - William M. Clemons
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
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Beck D, Vasisht N, Baglieri J, Monteferrante CG, van Dijl JM, Robinson C, Smith CJ. Ultrastructural characterisation of Bacillus subtilis TatA complexes suggests they are too small to form homooligomeric translocation pores. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1811-9. [PMID: 23567937 PMCID: PMC3988878 DOI: 10.1016/j.bbamcr.2013.03.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 03/27/2013] [Accepted: 03/28/2013] [Indexed: 11/29/2022]
Abstract
Tat-dependent protein transport permits the traffic of fully folded proteins across membranes in bacteria and chloroplasts. The mechanism by which this occurs is not understood. Current theories propose that a key step requires the coalescence of a substrate-binding TatC-containing complex with a TatA complex, which forms pores of varying sizes that could accommodate different substrates. We have studied the structure of the TatAd complex from Bacillus subtilis using electron microscopy to generate the first 3D model of a TatA complex from a Gram-positive bacterium. We observe that TatAd does not exhibit the remarkable heterogeneity of Escherichia coli TatA complexes but instead forms ring-shaped complexes of 7.5–9 nm diameter with potential pores of 2.5–3 nm diameter that are occluded at one end. Such structures are consistent with those seen for E. coli TatE complexes. Furthermore, the small diameter of the TatAd pore, and the homogeneous nature of the complexes, suggest that TatAd cannot form the translocation channel by itself. Biochemical data indicate that another B. subtilis TatA complex, TatAc, has similar properties, suggesting a common theme for TatA-type complexes from Bacillus. First 3D density maps of TatA-type complexes from Gram-positive organism TatAd forms ring-shaped complexes with potential pores of 2.5–3 nm diameters. The small diameter of TatAd channels apparently precludes passage of folded proteins. TatAc forms homogeneous complexes of < 100 kDa. Similarities between B. subtilis TatAd and TatAc suggest a common mechanism.
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Affiliation(s)
- Daniel Beck
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
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Freudl R. Leaving home ain't easy: protein export systems in Gram-positive bacteria. Res Microbiol 2013; 164:664-74. [PMID: 23541477 DOI: 10.1016/j.resmic.2013.03.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 02/05/2013] [Indexed: 10/27/2022]
Abstract
Transport of proteins into or across biological membranes is catalyzed by membrane-bound transport machineries. In Gram-positive bacteria, the vast majority of proteins are exported out of the cytosol by the conserved general secretion (Sec) system or, alternatively, by the twin-arginine translocation (Tat) system, that closely resemble their well-studied counterparts in Gram-negative bacteria. Besides these common major export routes, additional unique protein export systems (such as accessory Sec2 systems and/or type VII/WXG100 secretion systems) exist in some Gram-positive bacteria that are specifically involved in the secretion of limited subsets of proteins.
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Affiliation(s)
- Roland Freudl
- Institut für Bio- und Geowissenschaften 1, Biotechnologie, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.
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Monteferrante CG, MacKichan C, Marchadier E, Prejean MV, Carballido-López R, van Dijl JM. Mapping the twin-arginine protein translocation network of Bacillus subtilis. Proteomics 2013. [PMID: 23180473 DOI: 10.1002/pmic.201200416] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Bacteria employ twin-arginine translocation (Tat) pathways for the transport of folded proteins to extracytoplasmic destinations. In recent years, most studies on bacterial Tat pathways addressed the membrane-bound TatA(B)C subunits of the Tat translocase, and the specific interactions between this translocase and its substrate proteins. In contrast, relatively few studies investigated possible coactors in the TatA(B)C-dependent protein translocation process. The present studies were aimed at identifying interaction partners of the Tat pathway of Bacillus subtilis, which is a paradigm for studies on protein secretion by Gram-positive bacteria. Specifically, 36 interaction partners of the TatA and TatC subunits were identified by rigorous application of the yeast two-hybrid (Y2H) approach. Our Y2H analyses revealed that the three TatA isoforms of B. subtilis can form homo- and heterodimers. Subsequently, the secretion of the Tat substrates YwbN and PhoD was tested in mutant strains lacking genes for the TatAC interaction partners identified in our genome-wide Y2H screens. Our results show that the cell wall-bound protease WprA is important for YwbN secretion, and that the HemAT and CsbC proteins are required for PhoD secretion under phosphate starvation conditions. Taken together, our findings imply that the Bacillus Tat pathway is embedded in an intricate protein-protein interaction network.
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Affiliation(s)
- Carmine G Monteferrante
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
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van Dijl JM, Hecker M. Bacillus subtilis: from soil bacterium to super-secreting cell factory. Microb Cell Fact 2013; 12:3. [PMID: 23311580 PMCID: PMC3564730 DOI: 10.1186/1475-2859-12-3] [Citation(s) in RCA: 216] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 01/11/2013] [Indexed: 12/17/2022] Open
Abstract
The biotechnology industry has become a key element in modern societies. Within this industry, the production of recombinant enzymes and biopharmaceutical proteins is of major importance. The global markets for such recombinant proteins are growing rapidly and, accordingly, there is a continuous need for new production platforms that can deliver protein products in greater yields, with higher quality and at lower costs. This calls for the development of next-generation super-secreting cell factories. One of the microbial cell factories that can meet these challenges is the Gram-positive bacterium Bacillus subtilis, an inhabitant of the upper layers of the soil that has the capacity to secrete proteins in the gram per litre range. The engineering of B. subtilis into a next-generation super-secreting cell factory requires combined Systems and Synthetic Biology approaches. In this way, the bacterial protein secretion machinery can be optimized from the single molecule to the network level while, at the same time, taking into account the balanced use of cellular resources. Although highly ambitious, this is an achievable objective due to recent advances in functional genomics and Systems- and Synthetic Biological analyses of B. subtilis cells.
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Affiliation(s)
- Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P,O, box 30001, Groningen, 9700 RB, the Netherlands.
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Goosens VJ, Otto A, Glasner C, Monteferrante CC, van der Ploeg R, Hecker M, Becher D, van Dijl JM. Novel Twin-Arginine Translocation Pathway-Dependent Phenotypes of Bacillus subtilis Unveiled by Quantitative Proteomics. J Proteome Res 2013; 12:796-807. [DOI: 10.1021/pr300866f] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Vivianne J. Goosens
- Department of Medical Microbiology, University of Groningen, University Medical Center
Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen, The Netherlands
| | - Andreas Otto
- Institut für Mikrobiologie, Ernst-Moritz-Arndt Universität Greifswald, Friedrich-Ludwig-Jahn-Str.
15, D-17489 Greifswald, Germany
| | - Corinna Glasner
- Department of Medical Microbiology, University of Groningen, University Medical Center
Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen, The Netherlands
| | - Carmine C. Monteferrante
- Department of Medical Microbiology, University of Groningen, University Medical Center
Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen, The Netherlands
| | - René van der Ploeg
- Department of Medical Microbiology, University of Groningen, University Medical Center
Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen, The Netherlands
| | - Michael Hecker
- Institut für Mikrobiologie, Ernst-Moritz-Arndt Universität Greifswald, Friedrich-Ludwig-Jahn-Str.
15, D-17489 Greifswald, Germany
| | - Dörte Becher
- Institut für Mikrobiologie, Ernst-Moritz-Arndt Universität Greifswald, Friedrich-Ludwig-Jahn-Str.
15, D-17489 Greifswald, Germany
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center
Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen, The Netherlands
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Structure analysis of the membrane-bound PhoD signal peptide of the Tat translocase shows an N-terminal amphiphilic helix. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:3025-31. [DOI: 10.1016/j.bbamem.2012.08.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Revised: 07/09/2012] [Accepted: 08/02/2012] [Indexed: 11/19/2022]
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Identification and evaluation of twin-arginine translocase inhibitors. Antimicrob Agents Chemother 2012; 56:6223-34. [PMID: 23006747 DOI: 10.1128/aac.01575-12] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The twin-arginine translocase (TAT) in some bacterial pathogens, including Pseudomonas aeruginosa, Burkholderia pseudomallei, and Mycobacterium tuberculosis, contributes to pathogenesis by translocating extracellular virulence determinants across the inner membrane into the periplasm, thereby allowing access to the Xcp (type II) secretory system for further export in Gram-negative organisms, or directly to the outside surface of the cell, as in M. tuberculosis. TAT-mediated secretion appreciably contributes to virulence in both animal and plant models of bacterial infection. Consequently, TAT function is an attractive target for small-molecular-weight compounds that alone or in conjunction with extant antimicrobial agents could become novel therapeutics. The TAT-transported hemolytic phospholipase C (PlcH) of P. aeruginosa and its multiple orthologs produced by the above pathogens can be detected by an accurate and reproducible colorimetric assay using a synthetic substrate that detects phospholipase C activity. Such an assay could be an effective indicator of TAT function. Using carefully constructed recombinant strains to precisely control the expression of PlcH, we developed a high-throughput screening (HTS) assay to evaluate, in duplicate, >80,000 small-molecular-weight compounds as possible TAT inhibitors. Based on additional TAT-related functional assays, purified PlcH protein inhibition experiments, and repeat experiments of the initial screening assay, 39 compounds were selected from the 122 initial hits. Finally, to evaluate candidate inhibitors for TAT specificity, we developed a TAT titration assay that determines whether inhibition of TAT-mediated secretion can be overcome by increasing the levels of TAT expression. The compounds N-phenyl maleimide and Bay 11-7082 appear to directly affect TAT function based on this approach.
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Degradation of the twin-arginine translocation substrate YwbN by extracytoplasmic proteases of Bacillus subtilis. Appl Environ Microbiol 2012; 78:7801-4. [PMID: 22923395 DOI: 10.1128/aem.02023-12] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial twin-arginine translocases can export fully folded proteins from the cytoplasm. Such proteins are usually resistant to proteolysis. Here we show that multiple extracellular proteases degrade the B. subtilis Tat substrate YwbN. This suggests either that secreted YwbN is not fully folded or that folded YwbN exposes protease cleavage sites.
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40
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High-salinity growth conditions promote Tat-independent secretion of Tat substrates in Bacillus subtilis. Appl Environ Microbiol 2012; 78:7733-44. [PMID: 22923407 DOI: 10.1128/aem.02093-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Gram-positive bacterium Bacillus subtilis contains two Tat translocases, which can facilitate transport of folded proteins across the plasma membrane. Previous research has shown that Tat-dependent protein secretion in B. subtilis is a highly selective process and that heterologous proteins, such as the green fluorescent protein (GFP), are poor Tat substrates in this organism. Nevertheless, when expressed in Escherichia coli, both B. subtilis Tat translocases facilitated exclusively Tat-dependent export of folded GFP when the twin-arginine (RR) signal peptides of the E. coli AmiA, DmsA, or MdoD proteins were attached. Therefore, the present studies were aimed at determining whether the same RR signal peptide-GFP precursors would also be exported Tat dependently in B. subtilis. In addition, we investigated the secretion of GFP fused to the full-length YwbN protein, a strict Tat substrate in B. subtilis. Several investigated GFP fusion proteins were indeed secreted in B. subtilis, but this secretion was shown to be completely Tat independent. At high-salinity growth conditions, the Tat-independent secretion of GFP as directed by the RR signal peptides from the E. coli AmiA, DmsA, or MdoD proteins was significantly enhanced, and this effect was strongest in strains lacking the TatAy-TatCy translocase. This implies that high environmental salinity has a negative influence on the avoidance of Tat-independent secretion of AmiA-GFP, DmsA-GFP, and MdoD-GFP. We conclude that as-yet-unidentified control mechanisms reject the investigated GFP fusion proteins for translocation by the B. subtilis Tat machinery and, at the same time, set limits to their Tat-independent secretion, presumably via the Sec pathway.
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Monteferrante CG, Miethke M, van der Ploeg R, Glasner C, van Dijl JM. Specific targeting of the metallophosphoesterase YkuE to the bacillus cell wall requires the twin-arginine translocation system. J Biol Chem 2012; 287:29789-800. [PMID: 22767609 DOI: 10.1074/jbc.m112.378190] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The twin-arginine translocation (Tat) pathway is dedicated to the transport of fully folded proteins across the cytoplasmic membranes of many bacteria and the chloroplast thylakoidal membrane. Accordingly, Tat-dependently translocated proteins are known to be delivered to the periplasm of Gram-negative bacteria, the growth medium of Gram-positive bacteria, and the thylakoid lumen. Here, we present the first example of a protein, YkuE of Bacillus subtilis, that is specifically targeted by the Tat pathway to the cell wall of a Gram-positive bacterium. The cell wall binding of YkuE is facilitated by electrostatic interactions. Interestingly, under particular conditions, YkuE can also be targeted to the cell wall in a Tat-independent manner. The biological function of YkuE was so far unknown. Our present studies show that YkuE is a metal-dependent phosphoesterase that preferentially binds manganese and zinc.
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Affiliation(s)
- Carmine G Monteferrante
- Department of Medical Microbiology, University of Groningen and University Medical Center Groningen, Hanzeplein 1, P. O. Box 30001, 9700 RB Groningen, The Netherlands
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42
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Palmer T, Berks BC. The twin-arginine translocation (Tat) protein export pathway. Nat Rev Microbiol 2012; 10:483-96. [PMID: 22683878 DOI: 10.1038/nrmicro2814] [Citation(s) in RCA: 359] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The twin-arginine translocation (Tat) protein export system is present in the cytoplasmic membranes of most bacteria and archaea and has the highly unusual property of transporting fully folded proteins. The system must therefore provide a transmembrane pathway that is large enough to allow the passage of structured macromolecular substrates of different sizes but that maintains the impermeability of the membrane to ions. In the Gram-negative bacterium Escherichia coli, this complex task can be achieved by using only three small membrane proteins: TatA, TatB and TatC. In this Review, we summarize recent advances in our understanding of how this remarkable machine operates.
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Affiliation(s)
- Tracy Palmer
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.
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43
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Two-dimensional gel electrophoresis in bacterial proteomics. Protein Cell 2012; 3:346-63. [PMID: 22610887 DOI: 10.1007/s13238-012-2034-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Accepted: 02/22/2012] [Indexed: 02/01/2023] Open
Abstract
Two-dimensional gel electrophoresis (2-DE) is a gel-based technique widely used for analyzing the protein composition of biological samples. It is capable of resolving complex mixtures containing more than a thousand protein components into individual protein spots through the coupling of two orthogonal biophysical separation techniques: isoelectric focusing (first dimension) and polyacrylamide gel electrophoresis (second dimension). 2-DE is ideally suited for analyzing the entire expressed protein complement of a bacterial cell: its proteome. Its relative simplicity and good reproducibility have led to 2-DE being widely used for exploring proteomics within a wide range of environmental and medically-relevant bacteria. Here we give a broad overview of the basic principles and historical development of gel-based proteomics, and how this powerful approach can be applied for studying bacterial biology and physiology. We highlight specific 2-DE applications that can be used to analyze when, where and how much proteins are expressed. The links between proteomics, genomics and mass spectrometry are discussed. We explore how proteomics involving tandem mass spectrometry can be used to analyze (post-translational) protein modifications or to identify proteins of unknown origin by de novo peptide sequencing. The use of proteome fractionation techniques and non-gel-based proteomic approaches are also discussed. We highlight how the analysis of proteins secreted by bacterial cells (secretomes or exoproteomes) can be used to study infection processes or the immune response. This review is aimed at non-specialists who wish to gain a concise, comprehensive and contemporary overview of the nature and applications of bacterial proteomics.
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TatAc, the third TatA subunit of Bacillus subtilis, can form active twin-arginine translocases with the TatCd and TatCy subunits. Appl Environ Microbiol 2012; 78:4999-5001. [PMID: 22544248 DOI: 10.1128/aem.01108-12] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two independent twin-arginine translocases (Tat) for protein secretion were previously identified in the Gram-positive bacterium Bacillus subtilis. These consist of the TatAd-TatCd and TatAy-TatCy subunits. The function of a third TatA subunit named TatAc was unknown. Here, we show that TatAc can form active protein translocases with TatCd and TatCy.
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45
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Kassem II, Zhang Q, Rajashekara G. The twin-arginine translocation system: contributions to the pathobiology of Campylobacter jejuni. Future Microbiol 2012; 6:1315-27. [PMID: 22082291 DOI: 10.2217/fmb.11.107] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The twin-arginine translocation (Tat) system is specialized in the transport of folded proteins across the cytoplasmic membrane. Although the mechanisms that govern the Tat transport and its scope are not well understood, this system and its cognate substrates are involved in important functions that facilitate the adaptation and survival of bacteria. Evidence also exists that connects the Tat system to virulent traits of clinically relevant pathogens. Of interest is Campylobacter jejuni, an important foodborne pathogen that is capable of surviving in different hosts and environmental niches. Recent studies have shown that the Tat system in this bacterium mediates key metabolic and stress resistance traits. Furthermore, the majority of the identified Tat substrates in C. jejuni are cofactor-containing redox proteins that contribute to the bacterium?s branched electron transport chain, a component essential for survival under differing conditions. These studies as well as the absence of Tat homologs in the sequenced genomes of animals suggest that the Tat system might pose an attractive target for therapeutics against C. jejuni.
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Affiliation(s)
- Issmat I Kassem
- Food Animal Health Research Program, Ohio Agricultural Research & Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH 44691, USA
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van der Ploeg R, Barnett JP, Vasisht N, Goosens VJ, Pöther DC, Robinson C, van Dijl JM. Salt sensitivity of minimal twin arginine translocases. J Biol Chem 2011; 286:43759-43770. [PMID: 22041895 DOI: 10.1074/jbc.m111.243824] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bacterial twin arginine translocation (Tat) pathways have evolved to facilitate transport of folded proteins across membranes. Gram-negative bacteria contain a TatABC translocase composed of three subunits named TatA, TatB, and TatC. In contrast, the Tat translocases of most Gram-positive bacteria consist of only TatA and TatC subunits. In these minimal TatAC translocases, a bifunctional TatA subunit fulfils the roles of both TatA and TatB. Here we have probed the importance of conserved residues in the bifunctional TatAy subunit of Bacillus subtilis by site-specific mutagenesis. A set of engineered TatAy proteins with mutations in the cytoplasmic hinge and amphipathic helix regions were found to be inactive in protein translocation under standard growth conditions for B. subtilis or when heterologously expressed in Escherichia coli. Nevertheless, these mutated TatAy proteins did assemble into TatAy and TatAyCy complexes, and they facilitated membrane association of twin arginine precursor proteins in E. coli. Interestingly, most of the mutated TatAyCy translocases were salt-sensitive in B. subtilis. Similarly, the TatAC translocases of Bacillus cereus and Staphylococcus aureus were salt-sensitive when expressed in B. subtilis. Taken together, our present observations imply that salt-sensitive electrostatic interactions have critical roles in the preprotein translocation activity of certain TatAC type translocases from Gram-positive bacteria.
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Affiliation(s)
- René van der Ploeg
- Department of Medical Microbiology, University Medical Center Groningen and University of Groningen, 9700 RB Groningen, The Netherlands
| | - James P Barnett
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Nishi Vasisht
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Vivianne J Goosens
- Department of Medical Microbiology, University Medical Center Groningen and University of Groningen, 9700 RB Groningen, The Netherlands
| | - Dierk C Pöther
- Department of Medical Microbiology, University Medical Center Groningen and University of Groningen, 9700 RB Groningen, The Netherlands
| | - Colin Robinson
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University Medical Center Groningen and University of Groningen, 9700 RB Groningen, The Netherlands.
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47
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From the genome sequence to the protein inventory of Bacillus subtilis. Proteomics 2011; 11:2971-80. [DOI: 10.1002/pmic.201100090] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 04/07/2011] [Accepted: 04/20/2011] [Indexed: 12/12/2022]
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48
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Jiang X, Fares MA. Functional Diversification of the Twin-Arginine Translocation Pathway Mediates the Emergence of Novel Ecological Adaptations. Mol Biol Evol 2011; 28:3183-93. [DOI: 10.1093/molbev/msr154] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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49
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van der Ploeg R, Mäder U, Homuth G, Schaffer M, Denham EL, Monteferrante CG, Miethke M, Marahiel MA, Harwood CR, Winter T, Hecker M, Antelmann H, van Dijl JM. Environmental salinity determines the specificity and need for Tat-dependent secretion of the YwbN protein in Bacillus subtilis. PLoS One 2011; 6:e18140. [PMID: 21479178 PMCID: PMC3068169 DOI: 10.1371/journal.pone.0018140] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Accepted: 02/24/2011] [Indexed: 11/25/2022] Open
Abstract
Twin-arginine protein translocation (Tat) pathways are required for transport of folded proteins across bacterial, archaeal and chloroplast membranes. Recent studies indicate that Tat has evolved into a mainstream pathway for protein secretion in certain halophilic archaea, which thrive in highly saline environments. Here, we investigated the effects of environmental salinity on Tat-dependent protein secretion by the Gram-positive soil bacterium Bacillus subtilis, which encounters widely differing salt concentrations in its natural habitats. The results show that environmental salinity determines the specificity and need for Tat-dependent secretion of the Dyp-type peroxidase YwbN in B. subtilis. Under high salinity growth conditions, at least three Tat translocase subunits, namely TatAd, TatAy and TatCy, are involved in the secretion of YwbN. Yet, a significant level of Tat-independent YwbN secretion is also observed under these conditions. When B. subtilis is grown in medium with 1% NaCl or without NaCl, the secretion of YwbN depends strictly on the previously described “minimal Tat translocase” consisting of the TatAy and TatCy subunits. Notably, in medium without NaCl, both tatAyCy and ywbN mutants display significantly reduced exponential growth rates and severe cell lysis. This is due to a critical role of secreted YwbN in the acquisition of iron under these conditions. Taken together, our findings show that environmental conditions, such as salinity, can determine the specificity and need for the secretion of a bacterial Tat substrate.
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Affiliation(s)
- René van der Ploeg
- Department of Medical Microbiology, University Medical Center Groningen and University of Groningen, Groningen, The Netherlands
| | - Ulrike Mäder
- Interfaculty Institute for Genetics and Functional Genomics, Department for Functional Genomics, Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany
| | - Georg Homuth
- Interfaculty Institute for Genetics and Functional Genomics, Department for Functional Genomics, Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany
| | - Marc Schaffer
- Interfaculty Institute for Genetics and Functional Genomics, Department for Functional Genomics, Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany
| | - Emma L. Denham
- Department of Medical Microbiology, University Medical Center Groningen and University of Groningen, Groningen, The Netherlands
| | - Carmine G. Monteferrante
- Department of Medical Microbiology, University Medical Center Groningen and University of Groningen, Groningen, The Netherlands
| | - Marcus Miethke
- Department of Chemistry/Biochemistry, Philipps-University Marburg, Marburg, Germany
| | - Mohamed A. Marahiel
- Department of Chemistry/Biochemistry, Philipps-University Marburg, Marburg, Germany
| | - Colin R. Harwood
- Centre for Bacterial Cell Biology, Institute of Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Theresa Winter
- Institut für Mikrobiologie und Molekularbiologie, Ernst-Moritz-Arndt-Universität Greifswald, Greifswald, Germany
| | - Michael Hecker
- Institut für Mikrobiologie und Molekularbiologie, Ernst-Moritz-Arndt-Universität Greifswald, Greifswald, Germany
| | - Haike Antelmann
- Institut für Mikrobiologie und Molekularbiologie, Ernst-Moritz-Arndt-Universität Greifswald, Greifswald, Germany
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University Medical Center Groningen and University of Groningen, Groningen, The Netherlands
- * E-mail:
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50
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Robinson C, Matos CFRO, Beck D, Ren C, Lawrence J, Vasisht N, Mendel S. Transport and proofreading of proteins by the twin-arginine translocation (Tat) system in bacteria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1808:876-84. [PMID: 21126506 DOI: 10.1016/j.bbamem.2010.11.023] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Revised: 11/12/2010] [Accepted: 11/14/2010] [Indexed: 12/01/2022]
Abstract
The twin-arginine translocation (Tat) system operates in plant thylakoid membranes and the plasma membranes of most free-living bacteria. In bacteria, it is responsible for the export of a number of proteins to the periplasm, outer membrane or growth medium, selecting substrates by virtue of cleavable N-terminal signal peptides that contain a key twin-arginine motif together with other determinants. Its most notable attribute is its ability to transport large folded proteins (even oligomeric proteins) across the tightly sealed plasma membrane. In Gram-negative bacteria, TatABC subunits appear to carry out all of the essential translocation functions in the form of two distinct complexes at steady state: a TatABC substrate-binding complex and separate TatA complex. Several studies favour a model in which these complexes transiently coalesce to generate the full translocase. Most Gram-positive organisms possess an even simpler "minimalist" Tat system which lacks a TatB component and contains, instead, a bifunctional TatA component. These Tat systems may involve the operation of a TatAC complex together with a separate TatA complex, although a radically different model for TatAC-type systems has also been proposed. While bacterial Tat systems appear to require the presence of only a few proteins for the actual translocation event, there is increasing evidence for the operation of ancillary components that carry out sophisticated "proofreading" activities. These activities ensure that redox proteins are only exported after full assembly of the cofactor, thereby avoiding the futile export of apo-forms. This article is part of a Special Issue entitled Protein translocation across or insertion into membranes.
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Affiliation(s)
- Colin Robinson
- School of Life Sciences, University of Warwick, Coventry CV47AL, UK.
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