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Krasteva PV. Bacterial synthase-dependent exopolysaccharide secretion: a focus on cellulose. Curr Opin Microbiol 2024; 79:102476. [PMID: 38688160 DOI: 10.1016/j.mib.2024.102476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/24/2024] [Accepted: 04/03/2024] [Indexed: 05/02/2024]
Abstract
Bacterial biofilms are a prevalent multicellular life form in which individual members can undergo significant functional differentiation and are typically embedded in a complex extracellular matrix of proteinaceous fimbriae, extracellular DNA, and exopolysaccharides (EPS). Bacteria have evolved at least four major mechanisms for EPS biosynthesis, of which the synthase-dependent systems for bacterial cellulose secretion (Bcs) represent not only key biofilm determinants in a wide array of environmental and host-associated microbes, but also an important model system for the studies of processive glycan polymerization, cyclic diguanylate (c-di-GMP)-dependent synthase regulation, and biotechnological polymer applications. The secreted cellulosic chains can be decorated with additional chemical groups or can pack with various degrees of crystallinity depending on dedicated enzymatic complexes and/or cytoskeletal scaffolds. Here, I review recent progress in our understanding of synthase-dependent EPS biogenesis with a focus on common and idiosyncratic molecular mechanisms across diverse cellulose secretion systems.
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Affiliation(s)
- Petya V Krasteva
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, Pessac F-33600, France; 'Structural Biology of Biofilms' Group, European Institute of Chemistry and Biology (IECB), Pessac F-33600, France.
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2
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Verma P, Ho R, Chambers SA, Cegelski L, Zimmer J. Molecular insights into phosphoethanolamine cellulose formation and secretion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.04.588173. [PMID: 38645035 PMCID: PMC11030229 DOI: 10.1101/2024.04.04.588173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Phosphoethanolamine (pEtN) cellulose is a naturally occurring modified cellulose produced by several Enterobacteriaceae. The minimal components of the E. coli cellulose synthase complex include the catalytically active BcsA enzyme, an associated periplasmic semicircle of hexameric BcsB, as well as the outer membrane (OM)-integrated BcsC subunit containing periplasmic tetratricopeptide repeats (TPR). Additional subunits include BcsG, a membrane-anchored periplasmic pEtN transferase associated with BcsA, and BcsZ, a conserved periplasmic cellulase of unknown biological function. While events underlying the synthesis and translocation of cellulose by BcsA are well described, little is known about its pEtN modification and translocation across the cell envelope. We show that the N-terminal cytosolic domain of BcsA positions three copies of BcsG near the nascent cellulose polymer. Further, the terminal subunit of the BcsB semicircle tethers the N-terminus of a single BcsC protein to establish a trans-envelope secretion system. BcsC's TPR motifs bind a putative cello-oligosaccharide near the entrance to its OM pore. Additionally, we show that only the hydrolytic activity of BcsZ but not the subunit itself is necessary for cellulose secretion, suggesting a secretion mechanism based on enzymatic removal of mislocalized cellulose. Lastly, we introduce pEtN modification of cellulose in orthogonal cellulose biosynthetic systems by protein engineering.
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Affiliation(s)
- Preeti Verma
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA 22903, USA
| | - Ruoya Ho
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA 22903, USA
| | | | - Lynette Cegelski
- Department of Chemistry, Stanford University, Stanford, CA 94305, United States
| | - Jochen Zimmer
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA 22903, USA
- Howard Hughes Medical Institute
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3
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Yang L, Zhu X, Chen Y, Wang J. Enhanced bacterial cellulose production in Gluconacetobacter xylinus by overexpression of two genes (bscC and bcsD) and a modified static culture. Int J Biol Macromol 2024; 260:129552. [PMID: 38242407 DOI: 10.1016/j.ijbiomac.2024.129552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/09/2024] [Accepted: 01/15/2024] [Indexed: 01/21/2024]
Abstract
Bacterial cellulose (BC), a nanostructured material, is renowned for its excellent properties. However, its production by bacteria is costly due to low medium utilization and conversion rates. To enhance the yield of BC, this study aimed to increase BC yield through genetic modification, specifically by overexpressing bcsC and bcsD in Gluconacetobacter xylinus, and by developing a modified culture method to reduce medium viscosity by adding water during fermentation. As a result, BC yields of 5.4, 6.2, and 6.8 g/L were achieved from strains overexpressing genes bcsC, bcsD, and bcsCD, significantly surpassing the yield of 2.2 g/L from wild-type (WT) strains. In the modified culture, the BC yields of all four strains increased by >1 g/L with the addition of 20 mL of water during fermentation. Upon comparing the properties of BC, minimal differences were observed between the WT and pbcsC strains, as well as between the static and modified cultures. In contrast, BC produced by strains overexpressing bcsD had a denser microstructural network and exhibited demonstrated higher tensile strength and elongation-to-break. Compared to WT, BC from bcsD overexpressed strains also displayed enhanced crystallinity, higher degree of polymerization and improved thermal stability.
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Affiliation(s)
- Leyun Yang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China.
| | - Xinxin Zhu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China
| | - Yong Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China
| | - Jun Wang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
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4
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Bai L, Wu Y, Dai W, Zhang J, Zheng L, Cheng J. A simple and effective vascular network labeling method for transparent tissues of mice. JOURNAL OF BIOPHOTONICS 2023:e202300042. [PMID: 37017248 DOI: 10.1002/jbio.202300042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/26/2023] [Accepted: 03/29/2023] [Indexed: 06/19/2023]
Abstract
Vascular network labeling in transparent tissues provides more complete information on blood vessels. To achieve a fast and efficient method for vascular network labeling in transparent tissues, we compared various vascular labeling methods under different tissue clearing protocols. FITC-Dextran labeling and CUBIC cleaning treatment were found to be the best options for vascular network labeling in cleared mouse tissues. Satisfactory labeling of vascular networks in various organs can be achieved by selecting FITC-Dextran with different molecular weights and different administration methods.
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Affiliation(s)
- Lin Bai
- Key Laboratory of Transplant Engineering and Immunology, NHFPC, West China Hospital, Sichuan University, Chengdu, China
- Core Facility of West China Hospital, Sichuan University, Chengdu, China
| | - Yaping Wu
- Core Facility of West China Hospital, Sichuan University, Chengdu, China
| | - Wenshu Dai
- Key Laboratory of Transplant Engineering and Immunology, NHFPC, West China Hospital, Sichuan University, Chengdu, China
| | - Jie Zhang
- Key Laboratory of Transplant Engineering and Immunology, NHFPC, West China Hospital, Sichuan University, Chengdu, China
- Core Facility of West China Hospital, Sichuan University, Chengdu, China
| | - Lily Zheng
- TCM Regulating Metabolic Diseases Key Laboratory of Sichuan Province, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jingqiu Cheng
- Key Laboratory of Transplant Engineering and Immunology, NHFPC, West China Hospital, Sichuan University, Chengdu, China
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5
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Stephens Z, Wilson LFL, Zimmer J. Diverse mechanisms of polysaccharide biosynthesis, assembly and secretion across kingdoms. Curr Opin Struct Biol 2023; 79:102564. [PMID: 36870276 DOI: 10.1016/j.sbi.2023.102564] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 01/16/2023] [Accepted: 01/28/2023] [Indexed: 03/06/2023]
Abstract
Polysaccharides are essential biopolymers produced in all kingdoms of life. On the cell surface, they represent versatile architectural components, forming protective capsules and coats, cell walls, or adhesives. Extracellular polysaccharide (EPS) biosynthesis mechanisms differ based on the cellular localization of polymer assembly. Some polysaccharides are first synthesized in the cytosol and then extruded by ATP powered transporters [1]. In other cases, the polymers are assembled outside the cell [2], synthesized and secreted in a single step [3], or deposited on the cell surface via vesicular trafficking [4]. This review focuses on recent insights into the biosynthesis, secretion, and assembly of EPS in microbes, plants and vertebrates. We focus on comparing the sites of biosynthesis, secretion mechanisms, and higher-order EPS assemblies.
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Affiliation(s)
- Zachery Stephens
- Howard Hughes Medical Institute, University of Virginia School of Medicine, Charlottesville, VA, USA; Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, 480 Ray C. Hunt Dr., Charlottesville, VA 22908, USA
| | - Louis F L Wilson
- Howard Hughes Medical Institute, University of Virginia School of Medicine, Charlottesville, VA, USA; Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, 480 Ray C. Hunt Dr., Charlottesville, VA 22908, USA
| | - Jochen Zimmer
- Howard Hughes Medical Institute, University of Virginia School of Medicine, Charlottesville, VA, USA; Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, 480 Ray C. Hunt Dr., Charlottesville, VA 22908, USA.
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6
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Ahmad S, Sajjad M, Altayb HN, Sarim Imam S, Alshehri S, Ghoneim MM, Shahid S, Usman Mirza M, Shahid Nadeem M, Kazmi I, Waheed Akhtar M. Engineering processive cellulase of Clostridium thermocellum to divulge the role of the carbohydrate-binding module. Biotechnol Appl Biochem 2023; 70:290-305. [PMID: 35483889 DOI: 10.1002/bab.2352] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 04/05/2022] [Indexed: 11/11/2022]
Abstract
The processive cellulase (CelO) is an important modular enzyme of Clostridium thermocellum. To study the effect of the carbohydrate-binding module (CBM3b) on the catalytic domain of CelO (GH5), four engineered derivatives of CelO were designed by truncation and terminal fusion of CBM3b. These are CBM at the N-terminus, native form (CelO-BC, 62 kDa); catalytic domain only (CelO-C, 42 kDa); CBM at the C-terminus (CelO-CB, 54 kDa) and CBM attached at both termini (CelO-BCB, 73 kDa). All constructs were cloned into pET22b (+) and expressed in Escherichia coli BL21 (DE3) star. The expression levels of CelO-C, CelO-CB, CelO-BC, and CelO-BCB were 35%, 35%, 30%, and 20%, respectively. The enzyme activities of CelO-C, CelO-CB, CelO-BC, and CelO-BCB against 1% regenerated amorphous cellulose (RAC) were 860, 758, 985, and 1208 units per μmole of the enzyme, respectively. The enzymes were partially purified from the lysate of E. coli cells by heat treatment followed by anion exchange FPLC purification. Against RAC, CelO-C, CelO-CB, CelO-BC, and CelO-BCB showed KM values of 32, 33, 45, and 43 mg⋅mL-1 and Vmax values of 3571, 3846, 3571, and 4545 U⋅min-1 , respectively. CBM3b at the N-terminus of GH5 linked through a P/T-rich linker was found to enhance the catalytic activity and thermostability of the enzyme.
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Affiliation(s)
- Sajjad Ahmad
- School of Biological Science, University of the Punjab, Lahore, Pakistan
| | - Muhammad Sajjad
- School of Biological Science, University of the Punjab, Lahore, Pakistan
| | - Hisham N Altayb
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Syed Sarim Imam
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Sultan Alshehri
- Department of Pharmaceutical Sciences, College of Pharmacy, AlMaarefa University, Ad Diriyah, Saudi Arabia
| | - Mohammed M Ghoneim
- Department of Pharmaceutical Sciences, College of Pharmacy, AlMaarefa University, Ad Diriyah, Saudi Arabia
| | - Saher Shahid
- School of Biological Science, University of the Punjab, Lahore, Pakistan
| | - Muhammad Usman Mirza
- Department of Pharmaceutical and Pharmacological Sciences, Rega Institute for Medical Research, Laboratory of Medicinal Chemistry, University of Leuven, Leuven, Belgium
| | - Muhammad Shahid Nadeem
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Imran Kazmi
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
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7
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Kondo T, Nakamura Y, Nojima S, Yao M, Imai T. The BcsD subunit of type I bacterial cellulose synthase interacts dynamically with the BcsAB catalytic core complex. FEBS Lett 2022; 596:3069-3086. [PMID: 36103154 DOI: 10.1002/1873-3468.14495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/23/2022] [Accepted: 08/24/2022] [Indexed: 12/14/2022]
Abstract
Cellulose synthase has two distinct functions: synthesis of the cellulose molecule (polymerization) and assembling the synthesized cellulose chains into the crystalline microfibril (crystallization). In the type I bacterial cellulose synthase (Bcs) complex, four major subunits - BcsA, BcsB, BcsC and BcsD - work in a coordinated manner. This study showed that the crystallization subunit BcsD interacts with the polymerization complex BcsAB in two modes: direct protein-protein interactions and indirect interactions through the product cellulose. We hypothesized that the former and latter modes represent the basal and active states of type I bacterial cellulose synthase, respectively, and this dynamic behaviour of the BcsD protein regulates the crystallization process of cellulose chains.
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Affiliation(s)
- Tatsuya Kondo
- Research Institute for Sustainable Humanosphere (RISH), Kyoto University, Japan
| | - Yui Nakamura
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | - Shingo Nojima
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | - Min Yao
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | - Tomoya Imai
- Research Institute for Sustainable Humanosphere (RISH), Kyoto University, Japan
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8
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The TPR domain of PgaA is a multifunctional scaffold that binds PNAG and modulates PgaB-dependent polymer processing. PLoS Pathog 2022; 18:e1010750. [PMID: 35930610 PMCID: PMC9384988 DOI: 10.1371/journal.ppat.1010750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 08/17/2022] [Accepted: 07/19/2022] [Indexed: 11/30/2022] Open
Abstract
The synthesis of exopolysaccharides as biofilm matrix components by pathogens is a crucial factor for chronic infections and antibiotic resistance. Many periplasmic proteins involved in polymer processing and secretion in Gram-negative synthase dependent exopolysaccharide biosynthetic systems have been individually characterized. The operons responsible for the production of PNAG, alginate, cellulose and the Pel polysaccharide each contain a gene that encodes an outer membrane associated tetratricopeptide repeat (TPR) domain containing protein. While the TPR domain has been shown to bind other periplasmic proteins, the functional consequences of these interactions for the polymer remain poorly understood. Herein, we show that the C-terminal TPR region of PgaA interacts with the de-N-acetylase domain of PgaB, and increases its deacetylase activity. Additionally, we found that when the two proteins form a complex, the glycoside hydrolase activity of PgaB is also increased. To better understand structure-function relationships we determined the crystal structure of a stable TPR module, which has a conserved groove formed by three repeat motifs. Tryptophan quenching, mass spectrometry analysis and molecular dynamics simulation studies suggest that the crystallized TPR module can bind PNAG/dPNAG via its electronegative groove on the concave surface, and potentially guide the polymer through the periplasm towards the porin for export. Our results suggest a scaffolding role for the TPR domain that combines PNAG/dPNAG translocation with the modulation of its chemical structure by PgaB. Exopolysaccharides are an important component of the extracellular matrix of bacterial and fungal biofilms and provide protection against the host immune response and antibiotics. In Gram-negative bacteria, these polymers are synthesized in the inner membrane and translocated across the periplasm before being secreted across the outer membrane. The periplasm presents both a challenge as an additional environment to cross and an opportunity to chemically alter the polymer prior to secretion to render it more effective. This study focuses on a periplasmic alpha-helical repeat domain whose wide-spread homologues are involved in the export of many chemically distinct exopolysaccharides. We found that in E. coli this superhelical TPR domain acts as a scaffold that can bind the polymer PNAG and alter the enzymatic activity of PgaB, thus providing a means to affect the deacetylation level and chain length of the secreted polymer. Scaffold proteins are known as binding hubs within cellular pathways that often have a central regulatory function and facilitate evolution due to their repetitive modular building blocks. Our study sheds light on the principles of polysaccharide modification and export, which we hope will promote the development of applications against bacterial infections.
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Ishiya K, Kosaka H, Inaoka T, Kimura K, Nakashima N. Comparative Genome Analysis of Three Komagataeibacter Strains Used for Practical Production of Nata-de-Coco. Front Microbiol 2022; 12:798010. [PMID: 35185823 PMCID: PMC8855687 DOI: 10.3389/fmicb.2021.798010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 12/22/2021] [Indexed: 12/04/2022] Open
Abstract
We determined the whole genome sequences of three bacterial strains, designated as FNDCR1, FNDCF1, and FNDCR2, isolated from a practical nata-de-coco producing bacterial culture. Only FNDCR1 and FNDCR2 strains had the ability to produce cellulose. The 16S rDNA sequence and phylogenetic analysis revealed that all strains belonged to the Komagataeibacter genus but belonged to a different clade within the genus. Comparative genomic analysis revealed cross-strain distribution of duplicated sequences in Komagataeibacter genomes. It is particularly interesting that FNDCR1 has many duplicated sequences within the genome independently of the phylogenetic clade, suggesting that these duplications might have been obtained specifically for this strain. Analysis of the cellulose biosynthesis operon of the three determined strain genomes indicated that several cellulose synthesis-related genes, which are present in FNDCR1 and FNDCR2, were lost in the FNDCF1 strain. These findings reveal important genetic insights into practical nata de coco-producing bacteria that can be used in food development. Furthermore, our results also shed light on the variation in their cellulose-producing abilities and illustrate why genetic traits are unstable for Komagataeibacter and Komagataeibacter-related acetic acid bacteria.
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Affiliation(s)
- Koji Ishiya
- Bioproduction Research Institute, National Institute of Advanced Industrial Sciences and Technology (AIST), Sapporo, Japan
| | - Hideki Kosaka
- Research and Development Department, Fujicco Co., Ltd., Chuo-ku, Japan
| | - Takashi Inaoka
- Institute of Food Research, National Agriculture and Food Research Organization (NFRI/NARO), Tsukuba, Japan
| | - Keitarou Kimura
- Institute of Food Research, National Agriculture and Food Research Organization (NFRI/NARO), Tsukuba, Japan
| | - Nobutaka Nakashima
- Bioproduction Research Institute, National Institute of Advanced Industrial Sciences and Technology (AIST), Sapporo, Japan
- *Correspondence: Nobutaka Nakashima,
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10
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Fujiwara T, Fujishima A, Nakamura Y, Tajima K, Yao M. Structural snapshot of a glycoside hydrolase family 8 endo-β-1,4-glucanase capturing the state after cleavage of the scissile bond. Acta Crystallogr D Struct Biol 2022; 78:228-237. [PMID: 35102888 PMCID: PMC8805304 DOI: 10.1107/s2059798321012882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 12/03/2021] [Indexed: 11/10/2022] Open
Abstract
Bacterial cellulose (BC), which is produced by bacteria, is a biodegradable and biocompatible natural resource. Because of its remarkable physicochemical properties, BC has attracted attention for the development and manufacture of biomedical and industrial materials. In the BC production system, the enzyme endo-β-1,4-glucanase, which belongs to glycoside hydrolase family 8 (GH8), acts as a cleaner by trimming disordered cellulose fibers to produce high-quality BC. Understanding the molecular mechanism of the endo-β-1,4-glucanase would help in developing a reasonable biosynthesis of BC. Nevertheless, all of the steps in the reaction of this endo-β-1,4-glucanase are not clear. This study confirms the BC hydrolytic activity of the endo-β-1,4-glucanase from the BC-producing bacterium Enterobacter sp. CJF-002 (EbBcsZ) and reports crystal structures of EbBcsZ. Unlike in previously reported GH8 endo-β-1,4-glucanase structures, here the base catalyst was mutated (D242A) and the structure of this mutant bound to cellooligosaccharide [EbBcsZ(D242A)CPT] was analyzed. The EbBcsZ(D242A)CPT structure showed two cellooligosaccharides individually bound to the plus and minus subsites of EbBcsZ. The glucosyl unit in subsite −1 presented a distorted 5
S
1 conformation, a novel snapshot of a state immediately after scissile-bond cleavage. In combination with previous studies, the reaction process of endo-β-1,4-glucanase is described and the β-1,4-glucan-trimming mechanism of EbBcsZ is proposed. The EbBcsZ(D242A)CPT structure also showed an additional β-1,4-glucan binding site on the EbBcsZ surface, which may help to accept the substrate.
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Anderson AC, Burnett AJN, Constable S, Hiscock L, Maly KE, Weadge JT. A Mechanistic Basis for Phosphoethanolamine Modification of the Cellulose Biofilm Matrix in Escherichia coli. Biochemistry 2021; 60:3659-3669. [PMID: 34762795 DOI: 10.1021/acs.biochem.1c00605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Biofilms are communities of self-enmeshed bacteria in a matrix of exopolysaccharides. The widely distributed human pathogen and commensal Escherichia coli produces a biofilm matrix composed of phosphoethanolamine (pEtN)-modified cellulose and amyloid protein fibers, termed curli. The addition of pEtN to the cellulose exopolysaccharide is accomplished by the action of the pEtN transferase, BcsG, and is essential for the overall integrity of the biofilm. Here, using the synthetic co-substrates p-nitrophenyl phosphoethanolamine and β-d-cellopentaose, we demonstrate using an in vitro pEtN transferase assay that full activity of the pEtN transferase domain of BcsG from E. coli (EcBcsGΔN) requires Zn2+ binding, a catalytic nucleophile/acid-base arrangement (Ser278/Cys243/His396), disulfide bond formation, and other newly uncovered essential residues. We further confirm that EcBcsGΔN catalysis proceeds by a ping-pong bisubstrate-biproduct reaction mechanism and displays inefficient kinetic behavior (kcat/KM = 1.81 × 10-4 ± 2.81 × 10-5 M-1 s-1), which is typical of exopolysaccharide-modifying enzymes in bacteria. Thus, the results presented, especially with respect to donor binding (as reflected by KM), have importantly broadened our understanding of the substrate profile and catalytic mechanism of this class of enzymes, which may aid in the development of inhibitors targeting BcsG or other characterized members of the pEtN transferase family, including the intrinsic and mobile colistin resistance factors.
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12
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Takahama R, Kato H, Tajima K, Tagawa S, Kondo T. Biofabrication of a Hyaluronan/Bacterial Cellulose Composite Nanofibril by Secretion from Engineered Gluconacetobacter. Biomacromolecules 2021; 22:4709-4719. [PMID: 34705422 DOI: 10.1021/acs.biomac.1c00987] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Naturally occurring polysaccharides, such as cellulose, hemicellulose, and chitin, have roles in plant skeletons and/or related properties in living organisms. Their hierarchically regulated production systems show potential for designing nanocomposite fabrication using engineered microorganisms. This study has demonstrated that genetically engineered Gluconacetobacter hansenii (G. hansenii) individual cells can fabricate naturally composited nanofibrils by simultaneous production of hyaluronan (HA) and bacterial cellulose (BC). The cells were manipulated to contain hyaluronan synthase and UDP-glucose dehydrogenase genes, which are essential for HA biosynthesis. Fluorescence microscopic observations indicated the production of composited nanofibrils and suggested that HA secretion was associated with the cellulose secretory pathway in G. hansenii. The gel-like nanocomposite materials produced by the engineered G. hansenii exhibited superior properties compared with conventional in situ nanocomposites. This genetic engineering approach facilitates the use of G. hansenii for designing integrated cellulose-based nanomaterials.
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Affiliation(s)
- Ryo Takahama
- Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, West 5th, 744, Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Honami Kato
- Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, West 5th, 744, Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Kenji Tajima
- Faculty of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Satomi Tagawa
- Faculty of Agriculture, Kyushu University, West 5th, 744, Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Tetsuo Kondo
- Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, West 5th, 744, Motooka, Nishi-ku, Fukuoka 819-0395, Japan.,Faculty of Agriculture, Kyushu University, West 5th, 744, Motooka, Nishi-ku, Fukuoka 819-0395, Japan
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13
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Abidi W, Torres-Sánchez L, Siroy A, Krasteva PV. Weaving of bacterial cellulose by the Bcs secretion systems. FEMS Microbiol Rev 2021; 46:6388354. [PMID: 34634120 PMCID: PMC8892547 DOI: 10.1093/femsre/fuab051] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 10/08/2021] [Indexed: 12/13/2022] Open
Abstract
Cellulose is the most abundant biological compound on Earth and while it is the predominant building constituent of plants, it is also a key extracellular matrix component in many diverse bacterial species. While bacterial cellulose was first described in the 19th century, it was not until this last decade that a string of structural works provided insights into how the cellulose synthase BcsA, assisted by its inner-membrane partner BcsB, senses c-di-GMP to simultaneously polymerize its substrate and extrude the nascent polysaccharide across the inner bacterial membrane. It is now established that bacterial cellulose can be produced by several distinct types of cellulose secretion systems and that in addition to BcsAB, they can feature multiple accessory subunits, often indispensable for polysaccharide production. Importantly, the last years mark significant progress in our understanding not only of cellulose polymerization per se but also of the bigger picture of bacterial signaling, secretion system assembly, biofilm formation and host tissue colonization, as well as of structural and functional parallels of this dominant biosynthetic process between the bacterial and eukaryotic domains of life. Here, we review current mechanistic knowledge on bacterial cellulose secretion with focus on the structure, assembly and cooperativity of Bcs secretion system components.
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Affiliation(s)
- Wiem Abidi
- 'Structural Biology of Biofilms' group, European Institute of Chemistry and Biology (IECB), F-33600 Pessac, France.,Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France.,École doctorale 'Innovation thérapeutique: du fundamental à l'appliqué' (ITFA), Université Paris-Saclay, 92296, Chatenay-Malabry, France
| | - Lucía Torres-Sánchez
- 'Structural Biology of Biofilms' group, European Institute of Chemistry and Biology (IECB), F-33600 Pessac, France.,Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France.,École doctorale 'Innovation thérapeutique: du fundamental à l'appliqué' (ITFA), Université Paris-Saclay, 92296, Chatenay-Malabry, France
| | - Axel Siroy
- 'Structural Biology of Biofilms' group, European Institute of Chemistry and Biology (IECB), F-33600 Pessac, France.,Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France
| | - Petya Violinova Krasteva
- 'Structural Biology of Biofilms' group, European Institute of Chemistry and Biology (IECB), F-33600 Pessac, France.,Université de Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France
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14
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Molecular organization of the E. coli cellulose synthase macrocomplex. Nat Struct Mol Biol 2021; 28:310-318. [PMID: 33712813 PMCID: PMC9278871 DOI: 10.1038/s41594-021-00569-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 01/29/2021] [Indexed: 01/31/2023]
Abstract
Cellulose is frequently found in communities of sessile bacteria called biofilms. Escherichia coli and other enterobacteriaceae modify cellulose with phosphoethanolamine (pEtN) to promote host tissue adhesion. The E. coli pEtN cellulose biosynthesis machinery contains the catalytic BcsA-B complex that synthesizes and secretes cellulose, in addition to five other subunits. The membrane-anchored periplasmic BcsG subunit catalyzes pEtN modification. Here we present the structure of the roughly 1 MDa E. coli Bcs complex, consisting of one BcsA enzyme associated with six copies of BcsB, determined by single-particle cryo-electron microscopy. BcsB homo-oligomerizes primarily through interactions between its carbohydrate-binding domains as well as intermolecular beta-sheet formation. The BcsB hexamer creates a half spiral whose open side accommodates two BcsG subunits, directly adjacent to BcsA's periplasmic channel exit. The cytosolic BcsE and BcsQ subunits associate with BcsA's regulatory PilZ domain. The macrocomplex is a fascinating example of cellulose synthase specification.
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15
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Uto T, Ikeda Y, Sunagawa N, Tajima K, Yao M, Yui T. Molecular Dynamics Simulation of Cellulose Synthase Subunit D Octamer with Cellulose Chains from Acetic Acid Bacteria: Insight into Dynamic Behaviors and Thermodynamics on Substrate Recognition. J Chem Theory Comput 2021; 17:488-496. [PMID: 33382615 DOI: 10.1021/acs.jctc.0c01027] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The present study reports the building of a computerized model and molecular dynamics (MD) simulation of cellulose synthase subunit D octamer (CesD) from Komagataeibacter hansenii. CesD was complexed with four cellulose chains having DP = 12 (G12) by model building, which revealed unexpected S-shaped pathways with bending regions. Combined conventional and accelerated MD simulations of CesD complex models were carried out, while the pyranose ring conformations of the glucose residues were restrained to avoid undesirable deviations of the ring conformation from the 4C1 form. The N-terminal regions and parts of the secondary structures of CesD established appreciable contacts with the G12 chains. Hybrid quantum mechanical (QM) and molecular mechanical (MM) simulations of the CesD complex model were performed. Glucose residues located at the pathway bends exhibited reversible changes to the ring conformation into either skewed or boat forms, which might be related to the function of CesD in regulating microfibril production.
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Affiliation(s)
- Takuya Uto
- Organization for Promotion of Tenure Track, University of Miyazaki, Nishi 1-1 Gakuen-Kibanadai, Miyazaki 889-2192, Japan
| | - Yuki Ikeda
- Faculty of Engineering, University of Miyazaki, Nishi 1-1 Gakuen-Kibanadai, Miyazaki 889-2192, Japan
| | - Naoki Sunagawa
- Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kenji Tajima
- Faculty of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Min Yao
- Faculty of Advanced Life Science, Hokkaido University, N10W8, Kita-ku, Sapporo 060-0810, Japan
| | - Toshifumi Yui
- Faculty of Engineering, University of Miyazaki, Nishi 1-1 Gakuen-Kibanadai, Miyazaki 889-2192, Japan
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16
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Liston SD, Willis LM. Racing to build a wall: glycoconjugate assembly in Gram-positive and Gram-negative bacteria. Curr Opin Struct Biol 2021; 68:55-65. [PMID: 33429200 DOI: 10.1016/j.sbi.2020.11.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/20/2020] [Accepted: 11/22/2020] [Indexed: 12/17/2022]
Abstract
The last two years have seen major advances in understanding the structural basis of bacterial cell envelope glycoconjugate biosynthesis, including capsules, lipopolysaccharide, teichoic acid, cellulose, and peptidoglycan. The recent crystal and cryo-electron microscopy structures of proteins involved in the initial glycosyltransferase steps in the cytoplasm, the transport of large and small lipid-linked glycoconjugates across the inner membrane, the polymerization of glycans in the periplasm, and the export of molecules from the cell have shed light on the mechanisms by which cell envelope glycoconjugates are made. We discuss these recent advances and highlight remaining unanswered questions.
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Affiliation(s)
- Sean D Liston
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5G1M1, Canada
| | - Lisa M Willis
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G2T2, Canada; Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, T6G2T2, Canada; Women and Children's Health Research Institute, Edmonton, AB, T6G2T2, Canada.
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17
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Whitfield C, Wear SS, Sande C. Assembly of Bacterial Capsular Polysaccharides and Exopolysaccharides. Annu Rev Microbiol 2020; 74:521-543. [PMID: 32680453 DOI: 10.1146/annurev-micro-011420-075607] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Polysaccharides are dominant features of most bacterial surfaces and are displayed in different formats. Many bacteria produce abundant long-chain capsular polysaccharides, which can maintain a strong association and form a capsule structure enveloping the cell and/or take the form of exopolysaccharides that are mostly secreted into the immediate environment. These polymers afford the producing bacteria protection from a wide range of physical, chemical, and biological stresses, support biofilms, and play critical roles in interactions between bacteria and their immediate environments. Their biological and physical properties also drive a variety of industrial and biomedical applications. Despite the immense variation in capsular polysaccharide and exopolysaccharide structures, patterns are evident in strategies used for their assembly and export. This review describes recent advances in understanding those strategies, based on a wealth of biochemical investigations of select prototypes, supported by complementary insight from expanding structural biology initiatives. This provides a framework to identify and distinguish new systems emanating from genomic studies.
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Affiliation(s)
- Chris Whitfield
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada;
| | - Samantha S Wear
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada;
| | - Caitlin Sande
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada;
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18
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Caveney NA, Egan AJF, Ayala I, Laguri C, Robb CS, Breukink E, Vollmer W, Strynadka NCJ, Simorre JP. Structure of the Peptidoglycan Synthase Activator LpoP in Pseudomonas aeruginosa. Structure 2020; 28:643-650.e5. [PMID: 32320673 PMCID: PMC7267771 DOI: 10.1016/j.str.2020.03.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/15/2020] [Accepted: 03/24/2020] [Indexed: 12/23/2022]
Abstract
Peptidoglycan (PG) is an essential component of the bacterial cell wall and is assembled from a lipid II precursor by glycosyltransferase and transpeptidase reactions catalyzed in particular by bifunctional class A penicillin-binding proteins (aPBPs). In the major clinical pathogen Pseudomonas aeruginosa, PBP1B is anchored within the cytoplasmic membrane but regulated by a bespoke outer membrane-localized lipoprotein known as LpoP. Here, we report the structure of LpoP, showing an extended N-terminal, flexible tether followed by a well-ordered C-terminal tandem-tetratricopeptide repeat domain. We show that LpoP stimulates both PBP1B transpeptidase and glycosyltransferase activities in vitro and interacts directly via its C terminus globular domain with the central UB2H domain of PBP1B. Contrary to the situation in E. coli, P. aeruginosa CpoB does not regulate PBP1B/LpoP in vitro. We propose a mechanism that helps to underscore similarities and differences in class A PBP activation across Gram-negative bacteria. Structural organization of LpoP has been resolved PaPBP1B is directly stimulated by LpoP but not by PaCpoB in vitro LpoP likely interacts between the GTase and UB2H domains of PaPBP1B
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Affiliation(s)
- Nathanael A Caveney
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, The University of British Columbia, Vancouver V6T 1Z3 BC, Canada
| | - Alexander J F Egan
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK
| | - Isabel Ayala
- University of Grenoble Alpes, CNRS, CEA, IBS, 38000 Grenoble, France
| | - Cédric Laguri
- University of Grenoble Alpes, CNRS, CEA, IBS, 38000 Grenoble, France
| | - Craig S Robb
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, The University of British Columbia, Vancouver V6T 1Z3 BC, Canada
| | - Eefjan Breukink
- Department of Membrane Biochemistry and Biophysics, Utrecht University, Utrecht 3584 CH, The Netherlands
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK.
| | - Natalie C J Strynadka
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, The University of British Columbia, Vancouver V6T 1Z3 BC, Canada.
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19
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Suzuki R, Imamura T, Nonaga Y, Kusano H, Teramura H, Sekine KT, Yamashita T, Shimada H. A novel FLOURY ENDOSPERM2 (FLO2)-interacting protein, is involved in maintaining fertility and seed quality in rice. PLANT BIOTECHNOLOGY (TOKYO, JAPAN) 2020; 37:47-55. [PMID: 32362748 PMCID: PMC7193828 DOI: 10.5511/plantbiotechnology.19.1212b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 12/12/2019] [Indexed: 06/11/2023]
Abstract
Crop plants accumulate a large amount of storage starch and storage proteins in the endosperm. Genes involved in the biosynthesis of these substances work in concert during development of the rice endosperm. The rice flo2 mutant produces aberrant seeds with reduced grain quality. FLOURRY ENDOSPERM 2 (FLO2), the causative gene of the flo2 mutant, is considered to be a regulatory protein that controls the biosynthesis of seed storage substances. FLO2 contains tetratricopeptide repeat (TPR) motifs that may mediate protein-protein interactions. In this study, we identified the protein that interacts with the TPR motif of FLO2. We generated a transformant that produced the FLAG-tagged fusion FLO2 protein in the flo2 mutant and used this in the shotgun proteomic analysis. A protein, which we named FLOC1, interacted with FLO2. In vitro pull-down assays indicated that the TPR motif was involved in this interaction. A knock-down transformant of FLOC1 showed significantly reducted fertility and generation of seeds with abnormal features. These findings suggest that FLOC1 is involved not only in seed fertility but also in seed quality. These phenotypes were also observed on the RNAi transformants of the flo2 mutant although the effect of the flo2 mutation remained. these findings imply that there is a difference in the functions of FLO2 and FLOC1 although both of appear to be involved in the control of seed quality during seed formation.
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Affiliation(s)
- Rintaro Suzuki
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika, Tokyo 125-8585, Japan
| | - Tomohiro Imamura
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika, Tokyo 125-8585, Japan
| | - Yoko Nonaga
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika, Tokyo 125-8585, Japan
| | - Hiroaki Kusano
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika, Tokyo 125-8585, Japan
| | - Hiroshi Teramura
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika, Tokyo 125-8585, Japan
| | - Ken-Taro Sekine
- Faculty of Agriculture, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan
| | - Tetsuro Yamashita
- Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan
| | - Hiroaki Shimada
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika, Tokyo 125-8585, Japan
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20
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Characterization and optimization of production of bacterial cellulose from strain CGMCC 17276 based on whole-genome analysis. Carbohydr Polym 2020; 232:115788. [DOI: 10.1016/j.carbpol.2019.115788] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/23/2019] [Accepted: 12/26/2019] [Indexed: 12/14/2022]
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21
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Acheson JF, Derewenda ZS, Zimmer J. Architecture of the Cellulose Synthase Outer Membrane Channel and Its Association with the Periplasmic TPR Domain. Structure 2019; 27:1855-1861.e3. [PMID: 31604608 PMCID: PMC6939607 DOI: 10.1016/j.str.2019.09.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 08/12/2019] [Accepted: 09/16/2019] [Indexed: 02/06/2023]
Abstract
Extracellular bacterial cellulose contributes to biofilm stability and to the integrity of the bacterial cell envelope. In Gram-negative bacteria, cellulose is synthesized and secreted by a multi-component cellulose synthase complex. The BcsA subunit synthesizes cellulose and also transports the polymer across the inner membrane. Translocation across the outer membrane occurs through the BcsC porin, which extends into the periplasm via 19 tetra-tricopeptide repeats (TPR). We present the crystal structure of a truncated BcsC, encompassing the last TPR repeat and the complete outer membrane channel domain, revealing a 16-stranded, β barrel pore architecture. The pore is blocked by an extracellular gating loop, while the extended C terminus inserts deeply into the channel and positions a conserved Trp residue near its extracellular exit. The channel is lined with hydrophilic and aromatic residues suggesting a mechanism for facilitated cellulose diffusion based on aromatic stacking and hydrogen bonding.
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Affiliation(s)
- Justin F Acheson
- University of Virginia, School of Medicine, Department of Molecular Physiology and Biological Physics, Charlottesville, VA 22903, USA
| | - Zygmunt S Derewenda
- University of Virginia, School of Medicine, Department of Molecular Physiology and Biological Physics, Charlottesville, VA 22903, USA
| | - Jochen Zimmer
- University of Virginia, School of Medicine, Department of Molecular Physiology and Biological Physics, Charlottesville, VA 22903, USA.
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22
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Taweecheep P, Naloka K, Matsutani M, Yakushi T, Matsushita K, Theeragool G. Superfine bacterial nanocellulose produced by reverse mutations in the bcsC gene during adaptive breeding of Komagataeibacter oboediens. Carbohydr Polym 2019; 226:115243. [PMID: 31582059 DOI: 10.1016/j.carbpol.2019.115243] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 08/06/2019] [Accepted: 08/22/2019] [Indexed: 12/30/2022]
Abstract
Nonsense mutation in the bcsC gene occurred in the ethanol-adapted strain of Komagataeibacter oboediens MSKU 3, E3 strain, resulting in the loss of the function to produce BNC. In this study, we tried to restore the BNC-producing ability of E3 strain by the following adaptive mutation through repetitive static culture, and obtained four BNC-producing revertant strains, of which the bcsC gene had InDel mutations near the frameshift mutation region in E3 strain, resulting in several amino acid alterations compared with the BcsC of MSKU 3. Each revertant produced BNCs with different productivity on the static culture. Interestingly, one of the revertants, R37-9, produced BNC with a finer structure and narrower range of fibrils width, compared to others. The genome of R37-9 strain revealed only one amino acid substitution in the bcsC gene. Thus, we concluded that N713D mutation occurred in the bcsC gene is responsible for the finer fibrils structure.
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Affiliation(s)
- Pornchanok Taweecheep
- Interdisciplinary Graduate Program in Genetic Engineering, The Graduate School, Kasetsart University, Bangkok 10900, Thailand.
| | - Kallayanee Naloka
- Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.
| | - Minenosuke Matsutani
- Graduate School of Science and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8515, Japan.
| | - Toshiharu Yakushi
- Graduate School of Science and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8515, Japan; Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753-8515, Japan; Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi 753-8515, Japan.
| | - Kazunobu Matsushita
- Graduate School of Science and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8515, Japan; Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753-8515, Japan; Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi 753-8515, Japan.
| | - Gunjana Theeragool
- Interdisciplinary Graduate Program in Genetic Engineering, The Graduate School, Kasetsart University, Bangkok 10900, Thailand; Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.
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23
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Ryngajłło M, Jacek P, Cielecka I, Kalinowska H, Bielecki S. Effect of ethanol supplementation on the transcriptional landscape of bionanocellulose producer Komagataeibacter xylinus E25. Appl Microbiol Biotechnol 2019; 103:6673-6688. [PMID: 31168651 PMCID: PMC6667682 DOI: 10.1007/s00253-019-09904-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/30/2019] [Accepted: 05/06/2019] [Indexed: 10/26/2022]
Abstract
Ethanol exerts a strong positive effect on the cellulose yields from the widely exploited microbial producers of the Komagataeibacter genus. Ethanol is postulated to provide an alternative energy source, enabling effective use of glucose for cellulose biosynthesis rather than for energy acquisition. In this paper, we investigate the effect of ethanol supplementation on the global gene expression profile of Komagataeibacter xylinus E25 using RNA sequencing technology (RNA-seq). We demonstrate that when ethanol is present in the culture medium, glucose metabolism is directed towards cellulose production due to the induction of genes related to UDP-glucose formation and the repression of genes involved in glycolysis and acetan biosynthesis. Transcriptional changes in the pathways of cellulose biosynthesis and c-di-GMP metabolism are also described. The transcript level profiles suggest that Schramm-Hestrin medium supplemented with ethanol promotes bacterial growth by inducing protein biosynthesis and iron uptake. We observed downregulation of genes encoding transposases of the IS110 family which may provide one line of evidence explaining the positive effect of ethanol supplementation on the genotypic stability of K. xylinus E25. The results of this study increase knowledge and understanding of the regulatory effects imposed by ethanol on cellulose biosynthesis, providing new opportunities for directed strain improvement, scaled-up bionanocellulose production, and wider industrial exploitation of the Komagataeibacter species as bacterial cellulose producers.
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Affiliation(s)
- Małgorzata Ryngajłło
- Institute of Technical Biochemistry, Lodz University of Technology, B. Stefanowskiego 4/10, 90-924, Lodz, Poland.
| | - Paulina Jacek
- Institute of Technical Biochemistry, Lodz University of Technology, B. Stefanowskiego 4/10, 90-924, Lodz, Poland
| | - Izabela Cielecka
- Institute of Technical Biochemistry, Lodz University of Technology, B. Stefanowskiego 4/10, 90-924, Lodz, Poland
| | - Halina Kalinowska
- Institute of Technical Biochemistry, Lodz University of Technology, B. Stefanowskiego 4/10, 90-924, Lodz, Poland
| | - Stanisław Bielecki
- Institute of Technical Biochemistry, Lodz University of Technology, B. Stefanowskiego 4/10, 90-924, Lodz, Poland
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24
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Zimmer J. Structural features underlying recognition and translocation of extracellular polysaccharides. Interface Focus 2019; 9:20180060. [PMID: 30842868 DOI: 10.1098/rsfs.2018.0060] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2019] [Indexed: 12/31/2022] Open
Abstract
Essentially all living systems produce complex carbohydrates as an energy source, structural component, protective coat or adhesive for cell attachment. Many polysaccharides are displayed on the cell surface or are threaded through proteinaceous tunnels for degradation. Dictated by their chemical composition and mode of polymerization, the physical properties of complex carbohydrates differ substantially, from amphipathic water-insoluble polymers to highly hydrated hydrogel-forming macromolecules. Accordingly, diverse recognition and translocation mechanisms evolved to transport polysaccharides to their final destinations. This review will summarize and compare diverse polysaccharide transport mechanisms implicated in the biosynthesis and degradation of cell surface polymers in pro- and eukaryotes.
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Affiliation(s)
- Jochen Zimmer
- University of Virginia, 480 Ray C. Hunt Dr., Charlottesville, VA 22903, USA
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25
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Low KE, Howell PL. Gram-negative synthase-dependent exopolysaccharide biosynthetic machines. Curr Opin Struct Biol 2018; 53:32-44. [DOI: 10.1016/j.sbi.2018.05.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 05/03/2018] [Accepted: 05/07/2018] [Indexed: 11/16/2022]
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26
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Maeda K, Tamura J, Okuda Y, Narikawa R, Midorikawa T, Ikeuchi M. Genetic identification of factors for extracellular cellulose accumulation in the thermophilic cyanobacterium Thermosynechococcus vulcanus: proposal of a novel tripartite secretion system. Mol Microbiol 2018; 109:121-134. [PMID: 29688612 DOI: 10.1111/mmi.13977] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 04/12/2018] [Indexed: 12/19/2022]
Abstract
Cells of the thermophilic cyanobacterium Thermosynechococcus vulcanus strain RKN (NIES-2134) aggregate and produce extracellular cellulose under induced conditions of blue light and low temperature, and both aggregation and cellulose production require the cellulose synthase Tll0007 (XcsA) and photosensory diguanylate cyclases. However, overexpression of both the cellulose synthase and a constitutively active diguanylate cyclase was not sufficient to induce cellulose-mediated cell aggregation under normal growth conditions. Synteny analysis and gene knockout revealed that two putative genes, hlyD-like tlr0903 (xcsB) and endoglucanase-like tlr1902 (xcsC), are linked to tll0007, although they are located apart from tll0007 in the T. vulcanus genome. Gene knockdown revealed that tlr1605 (tolC) was essential for the cellulose-mediated cell aggregation. Low temperature induced marked upregulation of tlr0903, and overexpression of both tlr0903 (but not tlr1902) and diguanylate cyclase resulted in the strong cell aggregation and cellulose accumulation under normal conditions. Based on these and phylogenetic analysis, we propose that the cyanobacterial extracellular cellulose production is due to a novel variant of the bacterial tripartite secretion system.
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Affiliation(s)
- Kaisei Maeda
- Department of Life Sciences (Biology), Graduate School of Arts and Science, University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
| | - Jyunya Tamura
- Department of Life Sciences (Biology), Graduate School of Arts and Science, University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
| | - Yukiko Okuda
- Department of Life Sciences (Biology), Graduate School of Arts and Science, University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
| | - Rei Narikawa
- Department of Biological Science, Faculty of Science, Shizuoka University, Ohya, Suruga-ku, Shizuoka 422-8529, Japan
| | - Takafumi Midorikawa
- Department of Life Sciences (Biology), Graduate School of Arts and Science, University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
| | - Masahiko Ikeuchi
- Department of Life Sciences (Biology), Graduate School of Arts and Science, University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
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