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Silverio MP, Neumann T, Schaubruch K, Heermann R, Pérez-García P, Chow J, Streit WR. Metagenome-derived SusD-homologs affiliated with Bacteroidota bind to synthetic polymers. Appl Environ Microbiol 2024; 90:e0093324. [PMID: 38953372 PMCID: PMC11267923 DOI: 10.1128/aem.00933-24] [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: 05/17/2024] [Accepted: 06/04/2024] [Indexed: 07/04/2024] Open
Abstract
Starch utilization system (Sus)D-homologs are well known for their carbohydrate-binding capabilities and are part of the sus operon in microorganisms affiliated with the phylum Bacteroidota. Until now, SusD-like proteins have been characterized regarding their affinity toward natural polymers. In this study, three metagenomic SusD homologs (designated SusD1, SusD38489, and SusD70111) were identified and tested with respect to binding to natural and non-natural polymers. SusD1 and SusD38489 are cellulose-binding modules, while SusD70111 preferentially binds chitin. Employing translational fusion proteins with superfolder GFP (sfGFP), pull-down assays, and surface plasmon resonance (SPR) has provided evidence for binding to polyethylene terephthalate (PET) and other synthetic polymers. Structural analysis suggested that a Trp triad might be involved in protein adsorption. Mutation of these residues to Ala resulted in an impaired adsorption to microcrystalline cellulose (MC), but not so to PET and other synthetic polymers. We believe that the characterized SusDs, alongside the methods and considerations presented in this work, will aid further research regarding bioremediation of plastics. IMPORTANCE SusD1 and SusD38489 can be considered for further applications regarding their putative adsorption toward fossil-fuel based polymers. This is the first time that SusD homologs from the polysaccharide utilization loci (PUL), largely described for the phylum Bacteroidota, are characterized as synthetic polymer-binding proteins.
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Affiliation(s)
| | - Tabea Neumann
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Kirsten Schaubruch
- Institute of Molecular Physiology, Johannes-Gutenberg University of Mainz, Mainz, Germany
| | - Ralf Heermann
- Institute of Molecular Physiology, Johannes-Gutenberg University of Mainz, Mainz, Germany
| | - Pablo Pérez-García
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Jennifer Chow
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Wolfgang R. Streit
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
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2
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Mareček F, Terrapon N, Janeček Š. Two newly established and mutually related subfamilies GH13_48 and GH13_49 of the α-amylase family GH13. Appl Microbiol Biotechnol 2024; 108:415. [PMID: 38990377 PMCID: PMC11239784 DOI: 10.1007/s00253-024-13251-x] [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: 05/22/2024] [Revised: 06/26/2024] [Accepted: 07/01/2024] [Indexed: 07/12/2024]
Abstract
Currently, the main α-amylase family GH13 has been divided into 47 subfamilies in CAZy, with new subfamilies regularly emerging. The present in silico study was performed to highlight the groups, represented by the maltogenic amylase from Thermotoga neapolitana and the α-amylase from Haloarcula japonica, which are worth of creating their own new GH13 subfamilies. This enlarges functional annotation and thus allows more precise prediction of the function of putative proteins. Interestingly, those two share certain sequence features, e.g. the highly conserved cysteine in the second conserved sequence region (CSR-II) directly preceding the catalytic nucleophile, or the well-preserved GQ character of the end of CSR-VII. On the other hand, the two groups bear also specific and highly conserved positions that distinguish them not only from each other but also from representatives of remaining GH13 subfamilies established so far. For the T. neapolitana maltogenic amylase group, it is the stretch of residues at the end of CSR-V highly conserved as L-[DN]. The H. japonica α-amylase group can be characterized by a highly conserved [WY]-[GA] sequence at the end of CSR-II. Other specific sequence features include an almost fully conserved aspartic acid located directly preceding the general acid/base in CSR-III or well-preserved glutamic acid in CSR-IV. The assumption that these two groups represent two mutually related, but simultaneously independent GH13 subfamilies has been supported by phylogenetic analysis as well as by comparison of tertiary structures. The main α-amylase family GH13 has thus been expanded by two novel subfamilies GH13_48 and GH13_49. KEY POINTS: • In silico analysis of two groups of family GH13 members with characterized representatives • Identification of certain common, but also some specific sequence features in seven CSRs • Creation of two novel subfamilies-GH13_48 and GH13_49 within the CAZy database.
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Affiliation(s)
- Filip Mareček
- Laboratory of Protein Evolution, Institute of Molecular Biology, Slovak Academy of Sciences, 84551, Bratislava, Slovakia.
| | - Nicolas Terrapon
- Architecture Et Fonction Des Macromolécules Biologiques, UMR CNRS, Aix-Marseille University, USC INRAE, 13288, Marseille, France
| | - Štefan Janeček
- Laboratory of Protein Evolution, Institute of Molecular Biology, Slovak Academy of Sciences, 84551, Bratislava, Slovakia.
- Department of Biology, Institute of Biology and Biotechnology, Faculty of Natural Sciences, University of SS. Cyril and Methodius, 91701, Trnava, Slovakia.
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3
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Hameleers L, Gaenssle LA, Bertran‐Llorens S, Pijning T, Jurak E. Polysaccharide utilization loci encoded DUF1735 likely functions as membrane-bound spacer for carbohydrate active enzymes. FEBS Open Bio 2024; 14:1133-1146. [PMID: 38735878 PMCID: PMC11216935 DOI: 10.1002/2211-5463.13816] [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: 12/22/2023] [Revised: 03/17/2024] [Accepted: 04/29/2024] [Indexed: 05/14/2024] Open
Abstract
Proteins featuring the Domain of Unknown Function 1735 are frequently found in Polysaccharide Utilization Loci, yet their role remains unknown. The domain and vicinity analyzer programs we developed mine the Kyoto Encyclopedia of Genes and Genomes and UniProt to enhance the functional prediction of DUF1735. Our datasets confirmed the exclusive presence of DUF1735 in Bacteroidota genomes, with Bacteroidetes thetaiotaomicron harboring 46 copies. Notably, 97.8% of DUF1735 are encoded in PULs, and 89% are N-termini of multimodular proteins featuring C-termini like Laminin_G_3, F5/8-typeC, and GH18 domains. Predominantly possessing a predicted lipoprotein signal peptide and sharing an immunoglobulin-like β-sandwich fold with the BACON domain and the N-termini of SusE/F, DUF1735 likely functions as N-terminal, membrane-bound spacer for diverse C-termini involved in PUL-mediated carbohydrate utilization.
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Affiliation(s)
- Lisanne Hameleers
- Department of Bioproduct EngineeringUniversity of GroningenThe Netherlands
| | - Lucie A. Gaenssle
- Department of Bioproduct EngineeringUniversity of GroningenThe Netherlands
| | | | - Tjaard Pijning
- Department of Biomolecular X‐ray Crystallography, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)University of GroningenThe Netherlands
| | - Edita Jurak
- Department of Bioproduct EngineeringUniversity of GroningenThe Netherlands
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You Y, Kong H, Li C, Gu Z, Ban X, Li Z. Carbohydrate binding modules: Compact yet potent accessories in the specific substrate binding and performance evolution of carbohydrate-active enzymes. Biotechnol Adv 2024; 73:108365. [PMID: 38677391 DOI: 10.1016/j.biotechadv.2024.108365] [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: 12/11/2023] [Revised: 04/17/2024] [Accepted: 04/17/2024] [Indexed: 04/29/2024]
Abstract
Carbohydrate binding modules (CBMs) are independent non-catalytic domains widely found in carbohydrate-active enzymes (CAZymes), and they play an essential role in the substrate binding process of CAZymes by guiding the appended catalytic modules to the target substrates. Owing to their precise recognition and selective affinity for different substrates, CBMs have received increasing research attention over the past few decades. To date, CBMs from different origins have formed a large number of families that show a variety of substrate types, structural features, and ligand recognition mechanisms. Moreover, through the modification of specific sites of CBMs and the fusion of heterologous CBMs with catalytic domains, improved enzymatic properties and catalytic patterns of numerous CAZymes have been achieved. Based on cutting-edge technologies in computational biology, gene editing, and protein engineering, CBMs as auxiliary components have become portable and efficient tools for the evolution and application of CAZymes. With the aim to provide a theoretical reference for the functional research, rational design, and targeted utilization of novel CBMs in the future, we systematically reviewed the function-related characteristics and potentials of CAZyme-derived CBMs in this review, including substrate recognition and binding mechanisms, non-catalytic contributions to enzyme performances, module modifications, and innovative applications in various fields.
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Affiliation(s)
- Yuxian You
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Haocun Kong
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Caiming Li
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China
| | - Zhengbiao Gu
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Xiaofeng Ban
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Zhaofeng Li
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing 214200, China.
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5
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Brown HA, Morris AL, Pudlo NA, Hopkins AE, Martens EC, Golob JL, Koropatkin NM. Acarbose Impairs Gut Bacteroides Growth by Targeting Intracellular GH97 Enzymes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.20.595031. [PMID: 38826241 PMCID: PMC11142093 DOI: 10.1101/2024.05.20.595031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Acarbose is a type-2 diabetes medicine that inhibits dietary starch breakdown into glucose by inhibiting host amylase and glucosidase enzymes. Numerous gut species in the Bacteroides genus enzymatically break down starch and change in relative abundance within the gut microbiome in acarbose-treated individuals. To mechanistically explain this observation, we used two model starch-degrading Bacteroides, Bacteroides ovatus (Bo) and Bacteroides thetaiotaomicron (Bt). Bt growth is severely impaired by acarbose whereas Bo growth is not. The Bacteroides use a starch utilization system (Sus) to grow on starch. We hypothesized that Bo and Bt Sus enzymes are differentially inhibited by acarbose. Instead, we discovered that although acarbose primarily targets the Sus periplasmic GH97 enzymes in both organisms, the drug affects starch processing at multiple other points. Acarbose competes for transport through the Sus beta-barrel proteins and binds to the Sus transcriptional regulators. Further, Bo expresses a non-Sus GH97 (BoGH97D) when grown in starch with acarbose. The Bt homolog, BtGH97H, is not expressed in the same conditions, nor can overexpression of BoGH97D complement the Bt growth inhibition in the presence of acarbose. This work informs us about unexpected complexities of Sus function and regulation in Bacteroides, including variation between related species. Further, this indicates that the gut microbiome may be a source of variable response to acarbose treatment for diabetes.
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Affiliation(s)
- Haley A. Brown
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Adeline L. Morris
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Nicholas A. Pudlo
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Ashley E. Hopkins
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Eric C. Martens
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Jonathan L. Golob
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Internal Medicine, Division of Infectious Diseases, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Nicole M. Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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6
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Li S, Chen M, Wang Z, Abudourexiti W, Zhang L, Ding C, Ding L, Gong J. Ant may well destroy a whole dam: glycans of colonic mucus barrier disintegrated by gut bacteria. Microbiol Res 2024; 281:127599. [PMID: 38219635 DOI: 10.1016/j.micres.2023.127599] [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: 09/25/2023] [Revised: 12/29/2023] [Accepted: 12/30/2023] [Indexed: 01/16/2024]
Abstract
The colonic mucus layer plays a critical role in maintaining the integrity of the colonic mucosal barrier, serving as the primary defense against colonic microorganisms. Predominantly composed of mucin 2 (MUC2), a glycosylation-rich protein, the mucus layer forms a gel-like coating that covers the colonic epithelium surface. This layer provides a habitat for intestinal microorganisms, which can utilize mucin glycans present in the mucus layer as a sustainable source of nutrients. Additionally, metabolites produced by the microbiota during the metabolism of mucus glycans have a profound impact on host health. Under normal conditions, the production and consumption of mucus maintain a dynamic balance. However, several studies have demonstrated that certain factors, such as dietary fiber deficiency, can enhance the metabolism of mucus glycans by gut bacteria, thereby disturbing this balance and weakening the mucus barrier function of the mucus layer. To better understand the occurrence and development of colon-related diseases, it is crucial to investigate the complex metabolic patterns of mucus glycosylation by intestinal microorganisms. Our objective was to comprehensively review these patterns in order to clarify the effects of mucus layer glycan metabolism by intestinal microorganisms on the host.
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Affiliation(s)
- Song Li
- Department of General Surgery, Affiliated Jinling Hospital, Medical School, Nanjing University, Nanjing, China
| | - Mingfei Chen
- Department of General Surgery, Affiliated Jinling Hospital, Medical School, Nanjing University, Nanjing, China
| | - Zhongyuan Wang
- Department of General Surgery, Affiliated Jinling Hospital, Medical School, Nanjing University, Nanjing, China
| | - Waresi Abudourexiti
- Department of General Surgery, Affiliated Jinling Hospital, Medical School, Nanjing University, Nanjing, China
| | - Liang Zhang
- Department of Gastrointestinal Surgery, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical College, Jiangsu, China
| | - Chao Ding
- Department of General Surgery, Affiliated Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China.
| | - Lin Ding
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China; Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing 210023, China.
| | - Jianfeng Gong
- Department of General Surgery, Affiliated Jinling Hospital, Medical School, Nanjing University, Nanjing, China.
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7
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Yang J, Qin K, Wang Q, Yang X. Deciphering the nutritional strategies for polysaccharides effects on intestinal barrier in broilers: Selectively promote microbial ecosystems. Int J Biol Macromol 2024; 264:130677. [PMID: 38458298 DOI: 10.1016/j.ijbiomac.2024.130677] [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: 09/07/2023] [Revised: 03/03/2024] [Accepted: 03/05/2024] [Indexed: 03/10/2024]
Abstract
The gut microbiota, a complex and dynamic microbial ecosystem, plays a crucial role in regulating the intestinal barrier. Polysaccharide foraging is specifically dedicated to establishing and maintaining microbial communities, contributing to the shaping of the intestinal ecosystem and ultimately enhancing the integrity of the intestinal barrier. The utilization and regulation of individual polysaccharides often rely on distinct gut-colonizing bacteria. The products of their metabolism not only benefit the formation of the ecosystem but also facilitate cross-feeding partnerships. In this review, we elucidate the mechanisms by which specific bacteria degrade polysaccharides, and how polysaccharide metabolism shapes the microbial ecosystem through cross-feeding. Furthermore, we explore how selectively promoting microbial ecosystems and their metabolites contributes to improvements in the integrity of the intestinal barrier.
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Affiliation(s)
- Jiantao Yang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Kailong Qin
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Qianggang Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Xiaojun Yang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.
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8
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Kwain S, Dominy BN, Whitehead KJ, Miller BA, Whitehead DC. Exploring the interactive mechanism of acarbose with the amylase SusG in the starch utilization system of the human gut symbiont Bacteroides thetaiotaomicron through molecular modeling. Chem Biol Drug Des 2023; 102:486-499. [PMID: 37062591 DOI: 10.1111/cbdd.14251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 03/15/2023] [Accepted: 04/04/2023] [Indexed: 04/18/2023]
Abstract
The α-amylase, SusG, is a principal component of the Bacteroides thetaiotaomicron (Bt) starch utilization system (Sus) used to metabolize complex starch molecules in the human gastrointestinal (GI) tract. We previously reported the non-microbicidal growth inhibition of Bt by the acarbose-mediated arrest of the Sus as a potential therapeutic strategy. Herein, we report a computational approach using density functional theory (DFT), molecular docking, and molecular dynamics (MD) simulation to explore the interactive mechanism between acarbose and SusG at the atomic level in an effort to understand how acarbose shuts down the Bt Sus. The docking analysis reveals that acarbose binds orthosterically to SusG with a binding affinity of -8.3 kcal/mol. The MD simulation provides evidence of conformational variability of acarbose at the active site of SusG and also suggests that acarbose interacts with the main catalytic residues via a general acid-base double-displacement catalytic mechanism. These results suggest that small molecule competitive inhibition against the SusG protein could impact the entire Bt Sus and eliminate or reduce the system's ability to metabolize starch. This computational strategy could serve as a potential avenue for structure-based drug design to discover other small molecules capable of inhibiting the Sus of Bt with high potency, thus providing a holistic approach for selective modulation of the GI microbiota.
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Affiliation(s)
- Samuel Kwain
- Department of Chemistry, Clemson University, Clemson, South Carolina, USA
| | - Brian N Dominy
- Department of Chemistry, Clemson University, Clemson, South Carolina, USA
| | - Kristi J Whitehead
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, USA
| | - Brock A Miller
- Department of Chemistry, Clemson University, Clemson, South Carolina, USA
| | - Daniel C Whitehead
- Department of Chemistry, Clemson University, Clemson, South Carolina, USA
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9
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Brown HA, DeVeaux AL, Juliano BR, Photenhauer AL, Boulinguiez M, Bornschein RE, Wawrzak Z, Ruotolo BT, Terrapon N, Koropatkin NM. BoGH13A Sus from Bacteroides ovatus represents a novel α-amylase used for Bacteroides starch breakdown in the human gut. Cell Mol Life Sci 2023; 80:232. [PMID: 37500984 PMCID: PMC10540511 DOI: 10.1007/s00018-023-04812-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/15/2023] [Accepted: 05/17/2023] [Indexed: 07/29/2023]
Abstract
Members of the Bacteroidetes phylum in the human colon deploy an extensive number of proteins to capture and degrade polysaccharides. Operons devoted to glycan breakdown and uptake are termed polysaccharide utilization loci or PUL. The starch utilization system (Sus) is one such PUL and was initially described in Bacteroides thetaiotaomicron (Bt). BtSus is highly conserved across many species, except for its extracellular α-amylase, SusG. In this work, we show that the Bacteroides ovatus (Bo) extracellular α-amylase, BoGH13ASus, is distinguished from SusG in its evolutionary origin and its domain architecture and by being the most prevalent form in Bacteroidetes Sus. BoGH13ASus is the founding member of both a novel subfamily in the glycoside hydrolase family 13, GH13_47, and a novel carbohydrate-binding module, CBM98. The BoGH13ASus CBM98-CBM48-GH13_47 architecture differs from the CBM58 embedded within the GH13_36 of SusG. These domains adopt a distinct spatial orientation and invoke a different association with the outer membrane. The BoCBM98 binding site is required for Bo growth on polysaccharides and optimal enzymatic degradation thereof. Finally, the BoGH13ASus structure features bound Ca2+ and Mn2+ ions, the latter of which is novel for an α-amylase. Little is known about the impact of Mn2+ on gut bacterial function, much less on polysaccharide consumption, but Mn2+ addition to Bt expressing BoGH13ASus specifically enhances growth on starch. Further understanding of bacterial starch degradation signatures will enable more tailored prebiotic and pharmaceutical approaches that increase starch flux to the gut.
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Affiliation(s)
- Haley A Brown
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
| | - Anna L DeVeaux
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Brock R Juliano
- Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Amanda L Photenhauer
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Matthieu Boulinguiez
- Architecture et Fonction des Macromolécules Biologiques, UMR 7257, CNRS AMU; USC1408 INRAE, 13288, Marseille, France
| | | | - Zdzislaw Wawrzak
- Synchrotron Research Center, Life Science Collaborative Access Team, Northwestern University, Lemont, IL, USA
| | - Brandon T Ruotolo
- Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Nicolas Terrapon
- Architecture et Fonction des Macromolécules Biologiques, UMR 7257, CNRS AMU; USC1408 INRAE, 13288, Marseille, France
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
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Gharechahi J, Vahidi MF, Sharifi G, Ariaeenejad S, Ding XZ, Han JL, Salekdeh GH. Lignocellulose degradation by rumen bacterial communities: New insights from metagenome analyses. ENVIRONMENTAL RESEARCH 2023; 229:115925. [PMID: 37086884 DOI: 10.1016/j.envres.2023.115925] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/26/2023] [Accepted: 04/15/2023] [Indexed: 05/03/2023]
Abstract
Ruminant animals house a dense and diverse community of microorganisms in their rumen, an enlarged compartment in their stomach, which provides a supportive environment for the storage and microbial fermentation of ingested feeds dominated by plant materials. The rumen microbiota has acquired diverse and functionally overlapped enzymes for the degradation of plant cell wall polysaccharides. In rumen Bacteroidetes, enzymes involved in degradation are clustered into polysaccharide utilization loci to facilitate coordinated expression when target polysaccharides are available. Firmicutes use free enzymes and cellulosomes to degrade the polysaccharides. Fibrobacters either aggregate lignocellulose-degrading enzymes on their cell surface or release them into the extracellular medium in membrane vesicles, a mechanism that has proven extremely effective in the breakdown of recalcitrant cellulose. Based on current metagenomic analyses, rumen Bacteroidetes and Firmicutes are categorized as generalist microbes that can degrade a wide range of polysaccharides, while other members adapted toward specific polysaccharides. Particularly, there is ample evidence that Verrucomicrobia and Spirochaetes have evolved enzyme systems for the breakdown of complex polysaccharides such as xyloglucans, peptidoglycans, and pectin. It is concluded that diversity in degradation mechanisms is required to ensure that every component in feeds is efficiently degraded, which is key to harvesting maximum energy by host animals.
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Affiliation(s)
- Javad Gharechahi
- Human Genetics Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Mohammad Farhad Vahidi
- Animal Science Research Department, Qom Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Qom, Iran
| | - Golandam Sharifi
- Department of Basic Sciences, Encyclopedia Research Center, Institute for Humanities and Cultural Studies, Tehran, Iran
| | - Shohreh Ariaeenejad
- Department of Systems Biology, Agricultural Biotechnology Research Institute of Iran, Agricultural Research, Education, And Extension Organization, Karaj, Iran
| | - Xue-Zhi Ding
- Key Laboratory of Yak Breeding Engineering, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Lanzhou, 730050, China
| | - Jian-Lin Han
- Livestock Genetics Program, International Livestock Research, Institute (ILRI), 00100, Nairobi, Kenya; CAAS-ILRI Joint Laboratory on Livestock and Forage Genetic Resources, Institute of Animal Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100193, China.
| | - Ghasem Hosseini Salekdeh
- Department of Systems Biology, Agricultural Biotechnology Research Institute of Iran, Agricultural Research, Education, And Extension Organization, Karaj, Iran; School of Natural Sciences, Macquarie University, North Ryde, NSW, Australia.
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11
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Shi Q, Abdel-Hamid AM, Sun Z, Cheng Y, Tu T, Cann I, Yao B, Zhu W. Carbohydrate-binding modules facilitate the enzymatic hydrolysis of lignocellulosic biomass: Releasing reducing sugars and dissociative lignin available for producing biofuels and chemicals. Biotechnol Adv 2023; 65:108126. [PMID: 36921877 DOI: 10.1016/j.biotechadv.2023.108126] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 02/05/2023] [Accepted: 03/08/2023] [Indexed: 03/16/2023]
Abstract
The microbial decomposition and utilization of lignocellulosic biomass present in the plant tissues are driven by a series of carbohydrate active enzymes (CAZymes) acting in concert. As the non-catalytic domains widely found in the modular CAZymes, carbohydrate-binding modules (CBMs) are intimately associated with catalytic domains (CDs) that effect the diverse hydrolytic reactions. The CBMs function as auxiliary components for the recognition, adhesion, and depolymerization of the complex substrate mediated by the associated CDs. Therefore, CBMs are deemed as significant biotools available for enzyme engineering, especially to facilitate the enzymatic hydrolysis of dense and insoluble plant tissues to acquire more fermentable sugars. This review aims at presenting the taxonomies and biological properties of the CBMs currently curated in the CAZy database. The molecular mechanisms that CBMs use in assisting the enzymatic hydrolysis of plant polysaccharides and the regulatory factors of CBM-substrate interactions are outlined in detail. In addition, guidelines for the rational designs of CBM-fused CAZymes are proposed. Furthermore, the potential to harness CBMs for industrial applications, especially in enzymatic pretreatment of the recalcitrant lignocellulose, is evaluated. It is envisaged that the ideas outlined herein will aid in the engineering and production of novel CBM-fused enzymes to facilitate efficient degradation of lignocellulosic biomass to easily fermentable sugars for production of value-added products, including biofuels.
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Affiliation(s)
- Qicheng Shi
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Ahmed M Abdel-Hamid
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, IL 61801, USA
| | - Zhanying Sun
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China.
| | - Tao Tu
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Isaac Cann
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, IL 61801, USA; Department of Animal Science, University of Illinois at Urbana-Champaign, IL 61801, USA; Department of Microbiology, University of Illinois at Urbana-Champaign, IL 61801, USA; Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, IL 61801, USA; Center for East Asian and Pacific Studies, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Bin Yao
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
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12
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Bulka NR, Barbosa-Tessmann IP. Characterization of an Amylolytic Enzyme from Massilia timonae of the GH13_19 Subfamily with Mixed Maltogenic and CGTase Activity. Appl Biochem Biotechnol 2023; 195:2028-2056. [PMID: 36401066 DOI: 10.1007/s12010-022-04226-7] [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] [Accepted: 10/21/2022] [Indexed: 11/20/2022]
Abstract
This work reports the characterization of an amylolytic enzyme from the bacteria Massilia timonae CTI-57. A gene encoding this protein was expressed from the pTrcHis2B plasmid in Escherichia coli BL21 Star™ (DE3). The purified protein had 64 kDa, and its modeled structure showed a monomer with the conserved α-amylases structure composed of the domain A with the characteristic (β/α)8-barrel, the small domain B, and the domain C with an antiparallel beta-sheet. Phylogenetic analysis demonstrated that the expressed protein belongs to the GH13_19 subfamily of glycoside hydrolases. The ions Ca2+, Mn2+, Na+, Mg2+, Mo6+, and K+ did activate the purified enzyme, while EDTA and the ions Fe2+, Hg2+, Zn2+, and Cu2+ were strong inhibitors. SDS was also a strong inhibitor. The enzyme's optimal pH and temperature were 7.0 and 45 °C, respectively, and its Tm was 62.2 °C. The KM of the purified enzyme for starch was 13 mg/mL, and the Vmax was 0.24 μmol of reducing sugars released per min. The characterized enzyme presented higher specificity for maltodextrin and starch and produced maltose as the main starch hydrolysis product. This is the first characterized maltose-forming amylolytic enzyme from the GH13_19 subfamily. The purified enzyme produced β-cyclodextrin from starch and maltodextrin and could be considered a cyclodextrin glucanotransferase (CGTase). This is the first report of a GH13_19 subfamily enzyme with CGTase activity.
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Affiliation(s)
- Nathalia Rodrigues Bulka
- Department of Biochemistry, State University of Maringá, Av. Colombo, 5790, Maringá, PR, 87020-900, Brazil
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13
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Shao Y, Wang W, Hu Y, Gänzle MG. Characterization of the Glucan-Branching Enzyme GlgB Gene from Swine Intestinal Bacteria. Molecules 2023; 28:molecules28041881. [PMID: 36838868 PMCID: PMC9960391 DOI: 10.3390/molecules28041881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 02/08/2023] [Accepted: 02/14/2023] [Indexed: 02/18/2023] Open
Abstract
Starch hydrolysis by gut microbiota involves a diverse range of different enzymatic activities. Glucan-branching enzyme GlgB was identified as the most abundant glycosidase in Firmicutes in the swine intestine. GlgB converts α-(1→4)-linked amylose to form α-(1→4,6) branching points. This study aimed to characterize GlgB cloned from a swine intestinal metagenome and to investigate its potential role in formation of α-(1→4,6)-branched α-glucans from starch. The branching activity of purified GlgB was determined with six different starches and pure amylose by quantification of amylose after treatment. GlgB reduced the amylose content of all 6 starches and amylose by more than 85% and displayed a higher preference towards amylose. The observed activity on raw starch indicated a potential role in the primary starch degradation in the large intestine as an enzyme that solubilizes amylose. The oligosaccharide profile showed an increased concentration of oligosaccharide introduced by GlgB that is not hydrolyzed by intestinal enzymes. This corresponded to a reduced in vitro starch digestibility when compared to untreated starch. The study improves our understanding of colonic starch fermentation and may allow starch conversion to produce food products with reduced digestibility and improved quality.
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14
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A Novel Subfamily GH13_46 of the α-Amylase Family GH13 Represented by the Cyclomaltodextrinase from Flavobacterium sp. No. 92. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27248735. [PMID: 36557873 PMCID: PMC9781549 DOI: 10.3390/molecules27248735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 12/01/2022] [Accepted: 12/05/2022] [Indexed: 12/14/2022]
Abstract
In the CAZy database, the α-amylase family GH13 has already been divided into 45 subfamilies, with additional subfamilies still emerging. The presented in silico study was undertaken in an effort to propose a novel GH13 subfamily represented by the experimentally characterized cyclomaltodxtrinase from Flavobacterium sp. No. 92. Although most cyclomaltodextrinases have been classified in the subfamily GH13_20. This one has not been assigned any GH13 subfamily as yet. It possesses a non-specified immunoglobulin-like domain at its N-terminus mimicking a starch-binding domain (SBD) and the segment MPDLN in its fifth conserved sequence region (CSR) typical, however, for the subfamily GH13_36. The searches through sequence databases resulted in collecting a group of 108 homologs forming a convincing cluster in the evolutionary tree, well separated from all remaining GH13 subfamilies. The members of the newly proposed subfamily share a few exclusive sequence features, such as the "aromatic" end of the CSR-II consisting of two well-conserved tyrosines with either glycine, serine, or proline in the middle or a glutamic acid succeeding the catalytic proton donor in the CSR-III. Concerning the domain N of the representative cyclomaltodextrinase, docking trials with α-, β- and γ-cyclodextrins have indicated it may represent a new type of SBD. This new GH13 subfamily has been assigned the number GH13_46.
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15
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Geffroy L, Brown HA, DeVeaux AL, Koropatkin NM, Biteen JS. Single-molecule dynamics of surface lipoproteins in bacteroides indicate similarities and cooperativity. Biophys J 2022; 121:4644-4655. [PMID: 36266970 PMCID: PMC9748367 DOI: 10.1016/j.bpj.2022.10.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 10/12/2022] [Accepted: 10/17/2022] [Indexed: 12/15/2022] Open
Abstract
The gut microbiota comprises hundreds of species with a composition shaped by the available glycans. The well-studied starch utilization system (Sus) is a prototype for glycan uptake in the human gut bacterium Bacteroides thetaiotaomicron (Bt). Each Sus-like system includes outer-membrane proteins, which translocate glycan into the periplasm, and one or more cell-surface glycoside hydrolases, which break down a specific (cognate) polymer substrate. Although the molecular mechanisms of the Sus system are known, how the Sus and Sus-like proteins cooperate remains elusive. Previously, we used single-molecule and super-resolution fluorescence microscopy to show that SusG is mobile on the outer membrane and slows down in the presence of starch. Here, we compare the dynamics of three glycoside hydrolases: SusG, Bt4668, and Bt1760, which target starch, galactan, and levan, respectively. We characterized the diffusion of each surface hydrolase in the presence of its cognate glycan and found that all three enzymes are mostly immobile in the presence of the polysaccharide, consistent with carbohydrate binding. Moreover, experiments in glucose versus oligosaccharides suggest that the enzyme dynamics depend on their expression level. Furthermore, we characterized enzyme diffusion in a mixture of glycans and found that noncognate polysaccharides modify the dynamics of SusG and Bt1760 but not Bt4668. We investigated these systems with polysaccharide mixtures and genetic knockouts and found that noncognate polysaccharides modify hydrolase dynamics through some combination of nonspecific protein interactions and downregulation of the hydrolase. Overall, these experiments extend our understanding of how Sus-like lipoprotein dynamics can be modified by changing carbohydrate conditions and the expression level of the enzyme.
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Affiliation(s)
- Laurent Geffroy
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan
| | - Haley A Brown
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Anna L DeVeaux
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Julie S Biteen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan.
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16
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Butyrate-producing colonic clostridia: picky glycan utilization specialists. Essays Biochem 2022; 67:415-428. [PMID: 36350044 DOI: 10.1042/ebc20220125] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 10/18/2022] [Accepted: 10/21/2022] [Indexed: 11/10/2022]
Abstract
Abstract
Butyrate-producing human gut microbiota members are recognized for their strong association with a healthy immune-homeostasis and protection from inflammatory disorders and colorectal cancer. These effects are attributed to butyrate, the terminal electron sink of glycan fermentation by prevalent and abundant colonic Firmicutes from the Lachnospiraceae and Oscillospiraceae families. Remarkably, our insight into the glycan utilization mechanisms and preferences of butyrogenic Firmicutes remains very limited as compared with other gut symbionts, especially from the Bacteroides, Bifidobacterium, and Lactobacillus genera. Here, we summarize recent findings on the strategies that colonic butyrate producers have evolved to harvest energy from major dietary fibres, especially plant structural and storage glycans, such as resistant starch, xylans, and mannans. Besides dietary fibre, we also present the unexpected discovery of a conserved protein apparatus that confers the growth of butyrate producers on human milk oligosaccharides (HMOs), which are unique to mother’s milk. The dual dietary fibre/HMO utilization machinery attests the adaptation of this group to both the infant and adult guts. These finding are discussed in relation to the early colonization of butyrogenic bacteria and the maturation of the microbiota during the transition from mother’s milk to solid food. To date, the described butyrogenic Firmicutes are glycan utilization specialists that target only a few glycans in a highly competitive manner relying on co-regulated glycan utilization loci. We describe the common pillars of this machinery, highlighting butyrate producers as a source for discovery of biochemically and structurally novel carbohydrate active enzymes.
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17
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Christensen SJ, Madsen MS, Zinck SS, Hedberg C, Sørensen OB, Svensson B, Meyer AS. Enzymatic potato starch modification and structure-function analysis of six diverse GH77 4-alpha-glucanotransferases. Int J Biol Macromol 2022; 224:105-114. [DOI: 10.1016/j.ijbiomac.2022.10.107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 09/18/2022] [Accepted: 10/12/2022] [Indexed: 11/05/2022]
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18
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Functional Characterization of Recombinant Raw Starch Degrading α-Amylase from Roseateles terrae HL11 and Its Application on Cassava Pulp Saccharification. Catalysts 2022. [DOI: 10.3390/catal12060647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Exploring new raw starch-hydrolyzing α-amylases and understanding their biochemical characteristics are important for the utilization of starch-rich materials in bio-industry. In this work, the biochemical characteristics of a novel raw starch-degrading α-amylase (HL11 Amy) from Roseateles terrae HL11 was firstly reported. Evolutionary analysis revealed that HL11Amy was classified into glycoside hydrolase family 13 subfamily 32 (GH13_32). It contains four protein domains consisting of domain A, domain B, domain C and carbohydrate-binding module 20 (CMB20). The enzyme optimally worked at 50 °C, pH 4.0 with a specific activity of 6270 U/mg protein and 1030 raw starch-degrading (RSD) U/mg protein against soluble starch. Remarkably, HL11Amy exhibited activity toward both raw and gelatinized forms of various substrates, with the highest catalytic efficiency (kcat/Km) on starch from rice, followed by potato and cassava, respectively. HL11Amy effectively hydrolyzed cassava pulp (CP) hydrolysis, with a reducing sugar yield of 736 and 183 mg/g starch from gelatinized and raw CP, equivalent to 72% and 18% conversion based on starch content in the substrate, respectively. These demonstrated that HL11Amy represents a promising raw starch-degrading enzyme with potential applications in starch modification and cassava pulp saccharification.
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19
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Integrative structure determination reveals functional global flexibility for an ultra-multimodular arabinanase. Commun Biol 2022; 5:465. [PMID: 35577850 PMCID: PMC9110388 DOI: 10.1038/s42003-022-03054-z] [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: 12/27/2019] [Accepted: 07/15/2021] [Indexed: 11/08/2022] Open
Abstract
AbnA is an extracellular GH43 α-L-arabinanase from Geobacillus stearothermophilus, a key bacterial enzyme in the degradation and utilization of arabinan. We present herein its full-length crystal structure, revealing the only ultra-multimodular architecture and the largest structure to be reported so far within the GH43 family. Additionally, the structure of AbnA appears to contain two domains belonging to new uncharacterized carbohydrate-binding module (CBM) families. Three crystallographic conformational states are determined for AbnA, and this conformational flexibility is thoroughly investigated further using the "integrative structure determination" approach, integrating molecular dynamics, metadynamics, normal mode analysis, small angle X-ray scattering, dynamic light scattering, cross-linking, and kinetic experiments to reveal large functional conformational changes for AbnA, involving up to ~100 Å movement in the relative positions of its domains. The integrative structure determination approach demonstrated here may apply also to the conformational study of other ultra-multimodular proteins of diverse functions and structures.
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20
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Hedin N, Velazquez MB, Barchiesi J, Gomez-Casati DF, Busi MV. CBM20CP, a novel functional protein of starch metabolism in green algae. PLANT MOLECULAR BIOLOGY 2022; 108:363-378. [PMID: 34546521 DOI: 10.1007/s11103-021-01190-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 08/20/2021] [Indexed: 05/29/2023]
Abstract
Ostreococcus tauri is a picoalga that contains a small and compact genome, which resembles that of higher plants in the multiplicity of enzymes involved in starch synthesis (ADP-glucose pyrophosphorylase, ADPGlc PPase; granule bound starch synthase, GBSS; starch synthases, SSI, SSII, SSIII; and starch branching enzyme, SBE, between others), except starch synthase IV (SSIV). Although its genome is fully sequenced, there are still many genes and proteins to which no function was assigned. Here, we identify the OT_ostta06g01880 gene that encodes CBM20CP, a plastidial protein which contains a central carbohydrate binding domain of the CBM20 family, and a coiled coil domain at the C-terminus that lacks catalytic activity. We demonstrate that CBM20CP has the ability to bind starch, amylose and amylopectin with different affinities. Furthermore, this protein interacts with OsttaSSIII-B, increasing its binding to starch granules, its catalytic efficiency and promoting granule growth. The results allow us to postulate a functional role for CBM20CP in starch metabolism in green algae. KEY MESSAGE: CBM20CP, a plastidial protein that has a modular structure but lacks catalytic activity, regulates the synthesis of starch in Ostreococcus tauri.
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Affiliation(s)
- Nicolas Hedin
- CEFOBI - CONICET. Centro de Estudios Fotosintéticos y Bioquímicos - Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Santa Fe, Argentina
| | - Maria B Velazquez
- CEFOBI - CONICET. Centro de Estudios Fotosintéticos y Bioquímicos - Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Santa Fe, Argentina
| | - Julieta Barchiesi
- CEFOBI - CONICET. Centro de Estudios Fotosintéticos y Bioquímicos - Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Santa Fe, Argentina
| | - Diego F Gomez-Casati
- CEFOBI - CONICET. Centro de Estudios Fotosintéticos y Bioquímicos - Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Santa Fe, Argentina
| | - Maria V Busi
- CEFOBI - CONICET. Centro de Estudios Fotosintéticos y Bioquímicos - Consejo Nacional de Investigaciones Científicas y Técnicas. Facultad de Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Santa Fe, Argentina.
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21
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Muribaculaceae Genomes Assembled from Metagenomes Suggest Genetic Drivers of Differential Response to Acarbose Treatment in Mice. mSphere 2021; 6:e0085121. [PMID: 34851167 PMCID: PMC8636109 DOI: 10.1128/msphere.00851-21] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The drug acarbose is used to treat diabetes and, by inhibiting α-amylase in the small intestine, increases the amount of starch entering the lower digestive tract. This results in changes to the composition of the microbiota and their fermentation products. Acarbose also increases longevity in mice, an effect that has been correlated with increased production of the short-chain fatty acids propionate and butyrate. In experiments replicated across three study sites, two distantly related species in the bacterial family Muribaculaceae were dramatically more abundant in acarbose-treated mice, distinguishing these responders from other members of the family. Bacteria in the family Muribaculaceae are predicted to produce propionate as a fermentation end product and are abundant and diverse in the guts of mice, although few isolates are available. We reconstructed genomes from metagenomes (MAGs) for nine populations of Muribaculaceae to examine factors that distinguish species that respond positively to acarbose. We found two closely related MAGs (B1A and B1B) from one responsive species that both contain a polysaccharide utilization locus with a predicted extracellular α-amylase. These genomes also shared a periplasmic neopullulanase with another, distantly related MAG (B2) representative of the only other responsive species. This gene differentiated these three MAGs from MAGs representative of nonresponding species. Differential gene content in B1A and B1B may be associated with the inconsistent response of this species to acarbose across study sites. This work demonstrates the utility of culture-free genomics for inferring the ecological roles of gut bacteria, including their response to pharmaceutical perturbations. IMPORTANCE The drug acarbose is used to treat diabetes by preventing the breakdown of starch in the small intestine, resulting in dramatic changes in the abundance of some members of the gut microbiome and its fermentation products. In mice, several of the bacteria that respond most positively are classified in the family Muribaculaceae, members of which produce propionate as a primary fermentation product. Propionate has been associated with gut health and increased longevity in mice. We found that genomes of the most responsive Muribaculaceae showed signs of specialization for starch fermentation, presumably providing them a competitive advantage in the large intestine of animals consuming acarbose. Comparisons among genomes enhance existing models for the ecological niches occupied by members of this family. In addition, genes encoding one type of enzyme known to participate in starch breakdown were found in all three genomes from responding species but none of the other genomes.
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22
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Modulating Glycoside Hydrolase Activity between Hydrolysis and Transfer Reactions Using an Evolutionary Approach. Molecules 2021; 26:molecules26216586. [PMID: 34770995 PMCID: PMC8587830 DOI: 10.3390/molecules26216586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 01/02/2023] Open
Abstract
The proteins within the CAZy glycoside hydrolase family GH13 catalyze the hydrolysis of polysaccharides such as glycogen and starch. Many of these enzymes also perform transglycosylation in various degrees, ranging from secondary to predominant reactions. Identifying structural determinants associated with GH13 family reaction specificity is key to modifying and designing enzymes with increased specificity towards individual reactions for further applications in industrial, chemical, or biomedical fields. This work proposes a computational approach for decoding the determinant structural composition defining the reaction specificity. This method is based on the conservation of coevolving residues in spatial contacts associated with reaction specificity. To evaluate the algorithm, mutants of α-amylase (TmAmyA) and glucanotransferase (TmGTase) from Thermotoga maritima were constructed to modify the reaction specificity. The K98P/D99A/H222Q variant from TmAmyA doubled the transglycosydation/hydrolysis (T/H) ratio while the M279N variant from TmGTase increased the hydrolysis/transglycosidation ratio five-fold. Molecular dynamic simulations of the variants indicated changes in flexibility that can account for the modified T/H ratio. An essential contribution of the presented computational approach is its capacity to identify residues outside of the active center that affect the reaction specificity.
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23
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McKee LS, La Rosa SL, Westereng B, Eijsink VG, Pope PB, Larsbrink J. Polysaccharide degradation by the Bacteroidetes: mechanisms and nomenclature. ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:559-581. [PMID: 34036727 DOI: 10.1111/1758-2229.12980] [Citation(s) in RCA: 109] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 05/22/2021] [Accepted: 05/23/2021] [Indexed: 06/12/2023]
Abstract
The Bacteroidetes phylum is renowned for its ability to degrade a wide range of complex carbohydrates, a trait that has enabled its dominance in many diverse environments. The best studied species inhabit the human gut microbiome and use polysaccharide utilization loci (PULs), discrete genetic structures that encode proteins involved in the sensing, binding, deconstruction, and import of target glycans. In many environmental species, polysaccharide degradation is tightly coupled to the phylum-exclusive type IX secretion system (T9SS), which is used for the secretion of certain enzymes and is linked to gliding motility. In addition, within specific species these two adaptive systems (PULs and T9SS) are intertwined, with PUL-encoded enzymes being secreted by the T9SS. Here, we discuss the most noteworthy PUL and non-PUL mechanisms that confer specific and rapid polysaccharide degradation capabilities to the Bacteroidetes in a range of environments. We also acknowledge that the literature showcasing examples of PULs is rapidly expanding and developing a set of assumptions that can be hard to track back to original findings. Therefore, we present a simple universal description of conserved PUL functions and how they are determined, while proposing a common nomenclature describing PULs and their components, to simplify discussion and understanding of PUL systems.
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Affiliation(s)
- Lauren S McKee
- Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, 106 91, Sweden
- Wallenberg Wood Science Center, Stockholm, 100 44, Sweden
| | | | - Bjørge Westereng
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Vincent G Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Phillip B Pope
- Faculty of Biosciences, Norwegian University of Life Sciences, Ås, Norway
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Johan Larsbrink
- Wallenberg Wood Science Center, Stockholm, 100 44, Sweden
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, 412 96, Sweden
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24
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Chen Z, Geffroy L, Biteen JS. NOBIAS: Analyzing Anomalous Diffusion in Single-Molecule Tracks With Nonparametric Bayesian Inference. FRONTIERS IN BIOINFORMATICS 2021; 1. [PMID: 35498544 PMCID: PMC9053523 DOI: 10.3389/fbinf.2021.742073] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Single particle tracking (SPT) enables the investigation of biomolecular dynamics at a high temporal and spatial resolution in living cells, and the analysis of these SPT datasets can reveal biochemical interactions and mechanisms. Still, how to make the best use of these tracking data for a broad set of experimental conditions remains an analysis challenge in the field. Here, we develop a new SPT analysis framework: NOBIAS (NOnparametric Bayesian Inference for Anomalous Diffusion in Single-Molecule Tracking), which applies nonparametric Bayesian statistics and deep learning approaches to thoroughly analyze SPT datasets. In particular, NOBIAS handles complicated live-cell SPT data for which: the number of diffusive states is unknown, mixtures of different diffusive populations may exist within single trajectories, symmetry cannot be assumed between the x and y directions, and anomalous diffusion is possible. NOBIAS provides the number of diffusive states without manual supervision, it quantifies the dynamics and relative populations of each diffusive state, it provides the transition probabilities between states, and it assesses the anomalous diffusion behavior for each state. We validate the performance of NOBIAS with simulated datasets and apply it to the diffusion of single outer-membrane proteins in Bacteroides thetaiotaomicron. Furthermore, we compare NOBIAS with other SPT analysis methods and find that, in addition to these advantages, NOBIAS is robust and has high computational efficiency and is particularly advantageous due to its ability to treat experimental trajectories with asymmetry and anomalous diffusion.
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Affiliation(s)
- Ziyuan Chen
- Department of Biophysics, University of Michigan, Ann Arbor, MI, United States
| | - Laurent Geffroy
- Department of Chemistry, University of Michigan, Ann Arbor, MI, United States
| | - Julie S. Biteen
- Department of Biophysics, University of Michigan, Ann Arbor, MI, United States
- Department of Chemistry, University of Michigan, Ann Arbor, MI, United States
- *Correspondence: Julie S. Biteen,
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25
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Liu H, Shiver AL, Price MN, Carlson HK, Trotter VV, Chen Y, Escalante V, Ray J, Hern KE, Petzold CJ, Turnbaugh PJ, Huang KC, Arkin AP, Deutschbauer AM. Functional genetics of human gut commensal Bacteroides thetaiotaomicron reveals metabolic requirements for growth across environments. Cell Rep 2021; 34:108789. [PMID: 33657378 PMCID: PMC8121099 DOI: 10.1016/j.celrep.2021.108789] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 11/30/2020] [Accepted: 02/03/2021] [Indexed: 12/12/2022] Open
Abstract
Harnessing the microbiota for beneficial outcomes is limited by our poor understanding of the constituent bacteria, as the functions of most of their genes are unknown. Here, we measure the growth of a barcoded transposon mutant library of the gut commensal Bacteroides thetaiotaomicron on 48 carbon sources, in the presence of 56 stress-inducing compounds, and during mono-colonization of gnotobiotic mice. We identify 516 genes with a specific phenotype under only one or a few conditions, enabling informed predictions of gene function. For example, we identify a glycoside hydrolase important for growth on type I rhamnogalacturonan, a DUF4861 protein for glycosaminoglycan utilization, a 3-keto-glucoside hydrolase for disaccharide utilization, and a tripartite multidrug resistance system specifically for bile salt tolerance. Furthermore, we show that B. thetaiotaomicron uses alternative enzymes for synthesizing nitrogen-containing metabolic precursors based on ammonium availability and that these enzymes are used differentially in vivo in a diet-dependent manner.
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Affiliation(s)
- Hualan Liu
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Anthony L Shiver
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Morgan N Price
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Hans K Carlson
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Valentine V Trotter
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Yan Chen
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Veronica Escalante
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jayashree Ray
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kelsey E Hern
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Christopher J Petzold
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Peter J Turnbaugh
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Adam P Arkin
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Adam M Deutschbauer
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
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Multimodularity of a GH10 Xylanase Found in the Termite Gut Metagenome. Appl Environ Microbiol 2021; 87:AEM.01714-20. [PMID: 33187992 PMCID: PMC7848910 DOI: 10.1128/aem.01714-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/03/2020] [Indexed: 01/01/2023] Open
Abstract
Xylan is the major hemicellulosic polysaccharide in cereals and contributes to the recalcitrance of the plant cell wall toward degradation. Bacteroidetes, one of the main phyla in rumen and human gut microbiota, have been shown to encode polysaccharide utilization loci dedicated to the degradation of xylan. Here, we present the biochemical characterization of a xylanase encoded by a bacteroidetes strain isolated from the termite gut metagenome. The functional screening of a Pseudacanthotermes militaris termite gut metagenomic library revealed an array of xylan-degrading enzymes, including P. militaris 25 (Pm25), a multimodular glycoside hydrolase family 10 (GH10). Sequence analysis showed details of the unusual domain organization of this enzyme. It consists of one catalytic domain, which is intercalated by two carbohydrate binding modules (CBMs) from family 4. The genes upstream of the genes encoding Pm25 are susC-susD-unk, suggesting Pm25 is a Xyn10C-like enzyme belonging to a polysaccharide utilization locus. The majority of Xyn10C-like enzymes shared the same interrupted domain architecture and were vastly distributed in different xylan utilization loci found in gut Bacteroidetes, indicating the importance of this enzyme in glycan acquisition for gut microbiota. To understand its unusual multimodularity and the possible role of the CBMs, a detailed characterization of the full-length Pm25 and truncated variants was performed. Results revealed that the GH10 catalytic module is specific toward the hydrolysis of xylan. Ligand binding results indicate that the GH10 module and the CBMs act independently, whereas the tandem CBM4s act synergistically with each other and improve enzymatic activity when assayed on insoluble polysaccharides. In addition, we show that the UNK protein upstream of Pm25 is able to bind arabinoxylan. Altogether, these findings contribute to a better understanding of the potential role of Xyn10C-like proteins in xylan utilization systems of gut bacteria. IMPORTANCE Xylan is the major hemicellulosic polysaccharide in cereals and contributes to the recalcitrance of the plant cell wall toward degradation. Members of the Bacteroidetes, one of the main phyla in rumen and human gut microbiota, have been shown to encode polysaccharide utilization loci dedicated to the degradation of xylan. Here, we present the biochemical characterization of a xylanase encoded by a Bacteroidetes strain isolated from the termite gut metagenome. This xylanase is a multimodular enzyme, the sequence of which is interrupted by the insertion of two CBMs from family 4. Our results show that this enzyme resembles homologues that were shown to be important for xylan degradation in rumen or human diet and show that the CBM insertion in the middle of the sequence seems to be a common feature in xylan utilization systems. This study shed light on our understanding of xylan degradation and plant cell wall deconstruction, which can be applied to several applications in food, feed, and bioeconomy.
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Abstract
Resistant starch, microbiome, and precision modulation. Mounting evidence has positioned the gut microbiome as a nexus of health. Modulating its phylogenetic composition and function has become an attractive therapeutic prospect. Resistant starches (granular amylase-resistant α-glycans) are available as physicochemically and morphologically distinguishable products. Attempts to leverage resistant starch as microbiome-modifying interventions in clinical studies have yielded remarkable inter-individual variation. Consequently, their utility as a potential therapy likely depends predominantly on the selected resistant starch and the subject's baseline microbiome. The purpose of this review is to detail i) the heterogeneity of resistant starches, ii) how resistant starch is sequentially degraded and fermented by specialized gut microbes, and iii) how resistant starch interventions yield variable effects on the gut microbiome.
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Affiliation(s)
- Peter A. Dobranowski
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Alain Stintzi
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Ontario, Canada
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Cockburn DW, Cerqueira FM, Bahr C, Koropatkin NM. The structures of the GH13_36 amylases from Eubacterium rectale and Ruminococcus bromii reveal subsite architectures that favor maltose production. ACTA ACUST UNITED AC 2020. [DOI: 10.1515/amylase-2020-0003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractBacteria in the human gut including Ruminococcus bromii and Eubacterium rectale encode starch-active enzymes that dictate how these bacteria interact with starch to initiate a metabolic cascade that leads to increased butyrate. Here, we determined the structures of two predicted secreted glycoside hydrolase 13 subfamily 36 (GH13_36) enzymes: ErAmy13B complexed with maltotetraose from E. rectale and RbAmy5 from R. bromii. The structures show a limited binding pocket extending from –2 through +2 subsites with limited possibilities for substrate interaction beyond this, which contributes to the propensity for members of this family to produce maltose as their main product. The enzyme structures reveal subtle differences in the +1/+2 subsites that may restrict the recognition of larger starch polymers by ErAmy13B. Our bioinformatic analysis of the biochemically characterized members of the GH13_36 subfamily, which includes the cell-surface GH13 SusG from Bacteroides thetaiotaomicron, suggests that these maltogenic amylases (EC 3.2.1.133) are usually localized to the outside of the cell, display a range of substrate preferences, and most likely contribute to maltose liberation at the cell surface during growth on starch. A broader comparison between GH13_36 and other maltogenic amylase subfamilies explain how the activity profiles of these enzymes are influenced by their structures.
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Affiliation(s)
- Darrell W. Cockburn
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Food Science, Pennsylvania State University, University Park, PA 16802, USA
| | - Filipe M. Cerqueira
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Constance Bahr
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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29
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Božić N, Rozeboom HJ, Lončar N, Slavić MŠ, Janssen DB, Vujčić Z. Characterization of the starch surface binding site on Bacillus paralicheniformis α-amylase. Int J Biol Macromol 2020; 165:1529-1539. [PMID: 33058974 DOI: 10.1016/j.ijbiomac.2020.10.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 10/03/2020] [Accepted: 10/03/2020] [Indexed: 11/16/2022]
Abstract
α-Amylase from Bacillus paralicheniformis (BliAmy), belonging to GH13_5 subfamily of glycoside hydrolases, was proven to be a highly efficient raw starch digesting enzyme. The ability of some α-amylases to hydrolyze raw starch is related to the existence of surface binding sites (SBSs) for polysaccharides that can be distant from the active site. Crystallographic studies performed on BliAmy in the apo form and of enzyme bound with different oligosaccharides and oligosaccharide precursors revealed binding of these ligands to one SBS with two amino acids F257 and Y358 mainly involved in complex formation. The role of this SBS in starch binding and degradation was probed by designing enzyme variants mutated in this region (F257A and Y358A). Kinetic studies with different substrates show that starch binding through the SBS is disrupted in the mutants and that F257 and Y358 contributed cumulatively to binding and hydrolysis. Mutation of both sites (F257A/Y358A) resulted in a 5-fold lower efficacy with raw starch as substrate and at least 5.5-fold weaker binding compared to the wild type BliAmy, suggesting that the ability of BliAmy to hydrolyze raw starch with high efficiency is related to the level of its adsorption onto starch granules.
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Affiliation(s)
- Nataša Božić
- Department of Chemistry, Institute of Chemistry, Technology and Metallurgy, National Institute of the Republic of Serbia, University of Belgrade, Studentski trg 12-16, 11000 Belgrade, Serbia.
| | - Henriëtte J Rozeboom
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747AG Groningen, the Netherlands
| | - Nikola Lončar
- GECCO Biotech, Nijenborgh 4, Groningen 9747AG, the Netherlands
| | - Marinela Šokarda Slavić
- Department of Chemistry, Institute of Chemistry, Technology and Metallurgy, National Institute of the Republic of Serbia, University of Belgrade, Studentski trg 12-16, 11000 Belgrade, Serbia
| | - Dick B Janssen
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747AG Groningen, the Netherlands
| | - Zoran Vujčić
- Department of Biochemistry, Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, 11000 Belgrade, Serbia
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Glowacki RWP, Martens EC. If you eat it, or secrete it, they will grow: the expanding list of nutrients utilized by human gut bacteria. J Bacteriol 2020; 203:JB.00481-20. [PMID: 33168637 PMCID: PMC8092160 DOI: 10.1128/jb.00481-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In order to persist, successful bacterial inhabitants of the human gut need to adapt to changing nutrient conditions, which are influenced by host diet and a variety of other factors. For members of the Bacteroidetes and several other phyla, this has resulted in diversification of a variety of enzyme-based systems that equip them to sense and utilize carbohydrate-based nutrients from host, diet, and bacterial origin. In this review, we focus first on human gut Bacteroides and describe recent findings regarding polysaccharide utilization loci (PULs) and the mechanisms of the multi-protein systems they encode, including their regulation and the expanding diversity of substrates that they target. Next, we highlight previously understudied substrates such as monosaccharides, nucleosides, and Maillard reaction products that can also affect the gut microbiota by feeding symbionts that possess specific systems for their metabolism. Since some pathogens preferentially utilize these nutrients, they may represent nutrient niches competed for by commensals and pathogens. Finally, we address recent work to describe nutrient acquisition mechanisms in other important gut species such as those belonging to the Gram-positive anaerobic phyla Actinobacteria and Firmicutes, as well as the Proteobacteria Because gut bacteria contribute to many aspects of health and disease, we showcase advances in the field of synthetic biology, which seeks to engineer novel, diet-controlled nutrient utilization pathways within gut symbionts to create rationally designed live therapeutics.
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Affiliation(s)
- Robert W. P. Glowacki
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Eric C. Martens
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
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Structure-function analysis of silkworm sucrose hydrolase uncovers the mechanism of substrate specificity in GH13 subfamily 17 exo-α-glucosidases. J Biol Chem 2020; 295:8784-8797. [PMID: 32381508 PMCID: PMC7324511 DOI: 10.1074/jbc.ra120.013595] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/05/2020] [Indexed: 01/07/2023] Open
Abstract
The domestic silkworm Bombyx mori expresses two sucrose-hydrolyzing enzymes, BmSUH and BmSUC1, belonging to glycoside hydrolase family 13 subfamily 17 (GH13_17) and GH32, respectively. BmSUH has little activity on maltooligosaccharides, whereas other insect GH13_17 α-glucosidases are active on sucrose and maltooligosaccharides. Little is currently known about the structural mechanisms and substrate specificity of GH13_17 enzymes. In this study, we examined the crystal structures of BmSUH without ligands; in complexes with substrates, products, and inhibitors; and complexed with its covalent intermediate at 1.60-1.85 Å resolutions. These structures revealed that the conformations of amino acid residues around subsite -1 are notably different at each step of the hydrolytic reaction. Such changes have not been previously reported among GH13 enzymes, including exo- and endo-acting hydrolases, such as α-glucosidases and α-amylases. Amino acid residues at subsite +1 are not conserved in BmSUH and other GH13_17 α-glucosidases, but subsite -1 residues are absolutely conserved. Substitutions in three subsite +1 residues, Gln191, Tyr251, and Glu440, decreased sucrose hydrolysis and increased maltase activity of BmSUH, indicating that these residues are key for determining its substrate specificity. These results provide detailed insights into structure-function relationships in GH13 enzymes and into the molecular evolution of insect GH13_17 α-glucosidases.
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Brown HA, Koropatkin NM. Host glycan utilization within the Bacteroidetes Sus-like paradigm. Glycobiology 2020; 31:697-706. [PMID: 32518945 DOI: 10.1093/glycob/cwaa054] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/29/2020] [Accepted: 05/30/2020] [Indexed: 12/12/2022] Open
Abstract
The Bacteroidetes are numerically abundant Gram-negative organisms of the distal human gut with a greatly expanded capacity to degrade complex glycans. A subset of these are adept at scavenging host glycans within this environment, including mucin O-linked glycans, N-linked glycoproteins and highly sulfated glycosaminoglycans (GAGs) such as heparin (Hep) and chondroitin sulfate (CS). Several recent biochemical studies have revealed the specific polysaccharide utilization loci (PULs) within the model symbiont Bacteroides thetaiotaomicron for the deconstruction of these host glycans. Here we discuss the Sus-like paradigm that defines glycan uptake by the Bacteroidetes and the salient details of the PULs that target heparin/heparan sulfate (HS) and chondroitin sulfate/dermatan sulfate (DS)/hyaluronic acid (HA), respectively, in B. thetaiotaomicron. The ability of the Bacteroidetes to target highly sulfated host glycans is key to their success in the gut environment but can lead to inflammation in susceptible hosts. Therefore, our continued understanding of the molecular strategies employed by these bacteria to scavenge carbohydrate nutrition is likely to lead to novel ways to alter their metabolism to promote host health.
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Affiliation(s)
- Haley A Brown
- Department of Microbiology and Immunology, University of Michigan Medical School, 1150 West Medical Center Drive, Ann Arbor, MI 48109, USA
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, 1150 West Medical Center Drive, Ann Arbor, MI 48109, USA
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Zeng J, Guo J, Tu Y, Yuan L. Functional study of C-terminal domain of the thermoacidophilic raw starch-hydrolyzing α-amylase Gt-amy. Food Sci Biotechnol 2020; 29:409-418. [PMID: 32257525 DOI: 10.1007/s10068-019-00673-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 07/23/2019] [Accepted: 08/13/2019] [Indexed: 10/26/2022] Open
Abstract
Since the thermoacidophilic raw-starch hydrolyzing α-amylase Gt-amy can effectively hydrolyze corn starch under starch liquefaction conditions, it has potential for many industrial applications. To identify the raw starch-binding domain of Gt-amy, a C-terminal domain (CTD)-truncated mutant (Gt-amy-T) was constructed, and its enzymatic properties were compared with Gt-amy. In comparison to CTD of Gt-amy, which could effectively bind corn starch, the Gt-amy-T could not bind to and hydrolyze corn starch under similar conditions. In addition, Gt-amy-T showed significantly lower thermal activity and thermal stability. Using soluble starch as the substrate, the k cat of Gt-amy-T at 80 °C was approximately 77.9% of that of Gt-amy. The half-life of Gt-amy at 80 °C was 3 h, while that of Gt-amy-T was 2 h. These results reveal that the CTD plays a vital role in raw starch binding and degradation by Gt-amy and helps Gt-amy maintain thermal activity and stability.
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Affiliation(s)
- Jing Zeng
- 1Institute of Microbiology, Jiangxi Academy of Sciences, No. 7777 Changdong Avenue, Nanchang, 330096 Jiangxi Province China
| | - Jianjun Guo
- 1Institute of Microbiology, Jiangxi Academy of Sciences, No. 7777 Changdong Avenue, Nanchang, 330096 Jiangxi Province China
| | - Yikun Tu
- 2School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing, 211800 China
| | - Lin Yuan
- 1Institute of Microbiology, Jiangxi Academy of Sciences, No. 7777 Changdong Avenue, Nanchang, 330096 Jiangxi Province China
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Cerqueira FM, Photenhauer AL, Pollet RM, Brown HA, Koropatkin NM. Starch Digestion by Gut Bacteria: Crowdsourcing for Carbs. Trends Microbiol 2020; 28:95-108. [DOI: 10.1016/j.tim.2019.09.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/29/2019] [Accepted: 09/09/2019] [Indexed: 12/12/2022]
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Janeček Š, Mareček F, MacGregor EA, Svensson B. Starch-binding domains as CBM families-history, occurrence, structure, function and evolution. Biotechnol Adv 2019; 37:107451. [PMID: 31536775 DOI: 10.1016/j.biotechadv.2019.107451] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 08/01/2019] [Accepted: 09/15/2019] [Indexed: 01/05/2023]
Abstract
The term "starch-binding domain" (SBD) has been applied to a domain within an amylolytic enzyme that gave the enzyme the ability to bind onto raw, i.e. thermally untreated, granular starch. An SBD is a special case of a carbohydrate-binding domain, which in general, is a structurally and functionally independent protein module exhibiting no enzymatic activity but possessing potential to target the catalytic domain to the carbohydrate substrate to accommodate it and process it at the active site. As so-called families, SBDs together with other carbohydrate-binding modules (CBMs) have become an integral part of the CAZy database (http://www.cazy.org/). The first two well-described SBDs, i.e. the C-terminal Aspergillus-type and the N-terminal Rhizopus-type have been assigned the families CBM20 and CBM21, respectively. Currently, among the 85 established CBM families in CAZy, fifteen can be considered as families having SBD functional characteristics: CBM20, 21, 25, 26, 34, 41, 45, 48, 53, 58, 68, 69, 74, 82 and 83. All known SBDs, with the exception of the extra long CBM74, were recognized as a module consisting of approximately 100 residues, adopting a β-sandwich fold and possessing at least one carbohydrate-binding site. The present review aims to deliver and describe: (i) the SBD identification in different amylolytic and related enzymes (e.g., CAZy GH families) as well as in other relevant enzymes and proteins (e.g., laforin, the β-subunit of AMPK, and others); (ii) information on the position in the polypeptide chain and the number of SBD copies and their CBM family affiliation (if appropriate); (iii) structure/function studies of SBDs with a special focus on solved tertiary structures, in particular, as complexes with α-glucan ligands; and (iv) the evolutionary relationships of SBDs in a tree common to all SBD CBM families (except for the extra long CBM74). Finally, some special cases and novel potential SBDs are also introduced.
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Affiliation(s)
- Štefan Janeček
- Laboratory of Protein Evolution, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, SK-84551 Bratislava, Slovakia; Department of Biology, Faculty of Natural Sciences, University of SS. Cyril and Methodius, Nám. J. Herdu 2, SK-91701 Trnava, Slovakia.
| | - Filip Mareček
- Laboratory of Protein Evolution, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, SK-84551 Bratislava, Slovakia; Department of Biology, Faculty of Natural Sciences, University of SS. Cyril and Methodius, Nám. J. Herdu 2, SK-91701 Trnava, Slovakia
| | - E Ann MacGregor
- 2 Nicklaus Green, Livingston EH54 8RX, West Lothian, United Kingdom
| | - Birte Svensson
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 224, DK-2800 Kgs. Lyngby, Denmark
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36
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Wang X, Kan G, Shi C, Xie Q, Ju Y, Wang R, Qiao Y, Ren X. Purification and characterization of a novel wild-type α-amylase from Antarctic sea ice bacterium Pseudoalteromonas sp. M175. Protein Expr Purif 2019; 164:105444. [PMID: 31200017 DOI: 10.1016/j.pep.2019.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 06/09/2019] [Accepted: 06/10/2019] [Indexed: 10/26/2022]
Abstract
A novel wild-type α-amylase named wtAmy175 from Pseudoalteromonas sp. M175 strain was purified through ammonium sulphate precipitation, DEAE cellulose, and Sephadex G-75 sequentially (25.83-fold, 7.67%-yield) for biochemical characterization. SDS-PAGE and zymographic activity staining of purified enzyme showed a single band with a predicted molecular mass of about 61 kDa. The optimum temperature and pH for enzyme activity were 30 °C and 7.5, respectively. Additionally, the enzyme exhibited high activity and remarkable stability in 0-10 mM SDS. The values of Km and Vmax for soluble starch as substrate were 2.47 mg/ml and 0.103 mg/ml/min, respectively. Analysis of hydrolysis products of soluble starch and maltooligosaccharides showed that wtAmy175 cleaved the interior and the terminal α-1,4-glycosidic linkage in starch, and had transglycosylation activity. The result of fluorescence spectroscopy showed that wtAmy175 had strong binding affinity with soluble starch. In brief, this study discovered the first wild-type α-amylase so far with several distinctive properties of cold activity, SDS-resistance, and the mixed activity of α-amylase and α-glucosidase, suggesting that wtAmy175 possess high adaptive capability to endure harsh industrial conditions and would be an excellent candidate in detergent and textile industries.
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Affiliation(s)
- Xiaofei Wang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, PR China; School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, PR China
| | - Guangfeng Kan
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, PR China.
| | - Cuijuan Shi
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, PR China
| | - Qiuju Xie
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, PR China
| | - Yun Ju
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, PR China
| | - Ruiqi Wang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, PR China
| | - Yongping Qiao
- Wendeng Osteopath Hospital, Wendeng, 264400, PR China
| | - Xiulian Ren
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, PR China.
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Baroroh U, Yusuf M, Rachman SD, Ishmayana S, Hasan K, Subroto T. Molecular dynamics study to improve the substrate adsorption of Saccharomycopsis fibuligera R64 alpha-amylase by designing a new surface binding site. Adv Appl Bioinform Chem 2019; 12:1-13. [PMID: 31239719 PMCID: PMC6559716 DOI: 10.2147/aabc.s198110] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 03/19/2019] [Indexed: 11/23/2022] Open
Abstract
Background: Carbohydrate binding module (CBM) and surface binding site (SBS) are two important parts of amylase which respond to the raw starch digestion. They are related to the enzyme ability to adsorb and to catalyze the starch hydrolysis. However, starch processing is still expensive due to the high temperature in the gelatinization step. Therefore, direct starch digestion is more favorable. One of the solutions is to use α-amylase with high starch adsorptivity, which is expected to be capable of digesting starch below the gelatinization temperature. In Indonesia, Saccharomycopsis fibuligera R64 α-amylase (Sfamy R64) is one of the enzymes with the highest activity on starch. However, its raw starch adsorptivity was low. The aim of this study was to propose an in-silico model of Sfamy R64 mutant by introducing a new SBS using molecular dynamics (MD) simulation. Methods: The structural behavior of Sfamy R64 and positive control were studied using MD simulation. Furthermore, the mutants of Sfamy R64 were designed to have a stable SBS which mimics the positive control. The substrate affinity in all systems was evaluated using the molecular mechanics generalized Born surface area (MM/GBSA) method. Results: The stability of a new SBS constructed by seven substitutions and a loop insertion was improved throughout MD simulation. The substrate was consistently bound to the SBS over 55 ns of simulation, as compared to 14 ns in wild-type. The structural behavior of SBS in mutant and positive control was similar. The interaction energies of the positive control, wild-type, and mutant were −17.6, −5.2, and −8.2 kcal/mol, respectively. Conclusion: The enhanced substrate binding in the mutant, due to the existence of a new SBS, suggests the potential of improving starch adsorptivity of Sfamy R64. This result should be useful in developing an enzyme with better substrate adsorption based on the rational computer-aided molecular design approach.
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Affiliation(s)
- Umi Baroroh
- Biotechnology Master Program, Postgraduate School, Universitas Padjadjaran, Bandung 40132, West Java, Indonesia
| | - Muhammad Yusuf
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang 45363, West Java, Indonesia.,Research Center for Molecular Biotechnology and Bioinformatics, Universitas Padjadjaran, Bandung 40133, West Java, Indonesia
| | - Saadah Diana Rachman
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang 45363, West Java, Indonesia
| | - Safri Ishmayana
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang 45363, West Java, Indonesia
| | - Khomaini Hasan
- Faculty of Medicine, Universitas Jenderal Achmad Yani, Cimahi, West Java, Indonesia
| | - Toto Subroto
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang 45363, West Java, Indonesia.,Research Center for Molecular Biotechnology and Bioinformatics, Universitas Padjadjaran, Bandung 40133, West Java, Indonesia
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Characterization of a novel extracellular α-amylase from Ruminococcus bromii ATCC 27255 with neopullulanase-like activity. Int J Biol Macromol 2019; 130:605-614. [DOI: 10.1016/j.ijbiomac.2019.03.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 03/01/2019] [Accepted: 03/01/2019] [Indexed: 01/06/2023]
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39
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Deuschle F, Schiefner A, Skerra A. Structural differences between the ectodomains of murine and human CD98hc. Proteins 2019; 87:693-698. [DOI: 10.1002/prot.25686] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 04/02/2019] [Accepted: 04/04/2019] [Indexed: 11/09/2022]
Affiliation(s)
| | - André Schiefner
- Lehrstuhl für Biologische ChemieTechnische Universität München Freising Germany
| | - Arne Skerra
- Lehrstuhl für Biologische ChemieTechnische Universität München Freising Germany
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McKeen S, Young W, Mullaney J, Fraser K, McNabb WC, Roy NC. Infant Complementary Feeding of Prebiotics for theMicrobiome and Immunity. Nutrients 2019; 11:nu11020364. [PMID: 30744134 PMCID: PMC6412789 DOI: 10.3390/nu11020364] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 02/01/2019] [Accepted: 02/06/2019] [Indexed: 02/06/2023] Open
Abstract
Complementary feeding transitions infants from a milk-based diet to solid foods, providing essential nutrients to the infant and the developing gut microbiome while influencing immune development. Some of the earliest microbial colonisers readily ferment select oligosaccharides, influencing the ongoing establishment of the microbiome. Non-digestible oligosaccharides in prebiotic-supplemented formula and human milk oligosaccharides promote commensal immune-modulating bacteria such as Bifidobacterium, which decrease in abundance during weaning. Incorporating complex, bifidogenic, non-digestible carbohydrates during the transition to solid foods may present an opportunity to feed commensal bacteria and promote balanced concentrations of beneficial short chain fatty acid concentrations and vitamins that support gut barrier maturation and immunity throughout the complementary feeding window.
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Affiliation(s)
- Starin McKeen
- AgResearch, Food Nutrition & Health, Grasslands Research Centre, Private Bag 11008, Palmerston north4442, New Zealand.
- Riddet Institute, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand.
- High-Value Nutrition National Science Challenge, Auckland, New Zealand.
| | - Wayne Young
- AgResearch, Food Nutrition & Health, Grasslands Research Centre, Private Bag 11008, Palmerston north4442, New Zealand.
- Riddet Institute, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand.
- High-Value Nutrition National Science Challenge, Auckland, New Zealand.
| | - Jane Mullaney
- AgResearch, Food Nutrition & Health, Grasslands Research Centre, Private Bag 11008, Palmerston north4442, New Zealand.
- Riddet Institute, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand.
- High-Value Nutrition National Science Challenge, Auckland, New Zealand.
| | - Karl Fraser
- AgResearch, Food Nutrition & Health, Grasslands Research Centre, Private Bag 11008, Palmerston north4442, New Zealand.
- Riddet Institute, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand.
- High-Value Nutrition National Science Challenge, Auckland, New Zealand.
| | - Warren C McNabb
- Riddet Institute, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand.
- High-Value Nutrition National Science Challenge, Auckland, New Zealand.
| | - Nicole C Roy
- AgResearch, Food Nutrition & Health, Grasslands Research Centre, Private Bag 11008, Palmerston north4442, New Zealand.
- Riddet Institute, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand.
- High-Value Nutrition National Science Challenge, Auckland, New Zealand.
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Peng H, Zhai L, Xu S, Xu P, He C, Xiao Y, Gao Y. Efficient Hydrolysis of Raw Microalgae Starch by an α-Amylase (AmyP) of Glycoside Hydrolase Subfamily GH13_37. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:12748-12755. [PMID: 30441891 DOI: 10.1021/acs.jafc.8b03524] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Microalgae starch is receiving increasing attention as a renewable feedstock for biofuel production. Raw microalgae starch from Tetraselmis subcordiformis was proven to be very efficiently hydrolyzed by an α-amylase (AmyP) of glycoside hydrolase subfamily GH13_37 below the temperature of gelatinization (40 °C). The hydrolysis degree reached 74.4 ± 2.2% for 4% raw microalgae starch and 53.2 ± 1.7% for 8% raw microalgae starch after only 2 h. The hydrolysis efficiency was significantly stimulated by calcium ions. The enzyme catalysis of AmyP and its mutants (Q306A and E347A) suggested that calcium ions contributed to the hydrolysis of cyclic structures in raw microalgae starch by a distinctive calcium-binding site Ca2 of AmyP. The study explored raw microalgae starch as a new resource for cold enzymatic hydrolysis and extended our knowledge on the function of calcium in amylolytic enzyme.
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Affiliation(s)
- Hui Peng
- Anhui Key Laboratory of Modern Biomanufacturing, School of Life Sciences, School of Resources and Environmental Engineering , Anhui University , Hefei 230601 , Anhui P.R. China
| | - Lu Zhai
- Anhui Key Laboratory of Modern Biomanufacturing, School of Life Sciences, School of Resources and Environmental Engineering , Anhui University , Hefei 230601 , Anhui P.R. China
| | - Suo Xu
- Anhui Key Laboratory of Modern Biomanufacturing, School of Life Sciences, School of Resources and Environmental Engineering , Anhui University , Hefei 230601 , Anhui P.R. China
| | - Peng Xu
- Anhui Key Laboratory of Modern Biomanufacturing, School of Life Sciences, School of Resources and Environmental Engineering , Anhui University , Hefei 230601 , Anhui P.R. China
| | - Chao He
- Anhui Key Laboratory of Modern Biomanufacturing, School of Life Sciences, School of Resources and Environmental Engineering , Anhui University , Hefei 230601 , Anhui P.R. China
| | - Yazhong Xiao
- Anhui Key Laboratory of Modern Biomanufacturing, School of Life Sciences, School of Resources and Environmental Engineering , Anhui University , Hefei 230601 , Anhui P.R. China
| | - Yi Gao
- Anhui Key Laboratory of Modern Biomanufacturing, School of Life Sciences, School of Resources and Environmental Engineering , Anhui University , Hefei 230601 , Anhui P.R. China
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Surface Exposure and Packing of Lipoproteins into Outer Membrane Vesicles Are Coupled Processes in Bacteroides. mSphere 2018; 3:3/6/e00559-18. [PMID: 30404931 PMCID: PMC6222051 DOI: 10.1128/msphere.00559-18] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Species from the Bacteroides genus are predominant members of the human gut microbiota. OMVs in Bacteroides have been shown to be important for the homeostasis of complex host-commensal relationships, mainly involving immune tolerance and protection from disease. OMVs carry many enzymatic activities involved in the cleavage of complex polysaccharides and have been proposed as public goods that can provide growth to other bacterial species by release of polysaccharide breakdown products into the gut lumen. This work shows that the presence of a negatively charged rich amino acid motif (LES) is required for efficient packing of the surface-exposed alpha-amylase SusG into OMVs. Our findings strongly suggest that surface exposure is coupled to packing of Bacteroides lipoproteins into OMVs. This is the first step in the generation of tailor-made probiotic interventions that can exploit LES-related sequences to generate Bacteroides strains displaying proteins of interest in OMVs. Outer membrane vesicles (OMVs) are spherical structures derived from the outer membranes (OMs) of Gram-negative bacteria. Bacteroides spp. are prominent components of the human gut microbiota, and OMVs produced by these species are proposed to play key roles in gut homeostasis. OMV biogenesis in Bacteroides is a poorly understood process. Here, we revisited the protein composition of Bacteroides thetaiotaomicron OMVs by mass spectrometry. We confirmed that OMVs produced by this organism contain large quantities of glycosidases and proteases, with most of them being lipoproteins. We found that most of these OMV-enriched lipoproteins are encoded by polysaccharide utilization loci (PULs), such as the sus operon. We examined the subcellular locations of the components of the Sus system and found a split localization; the alpha-amylase SusG is highly enriched in OMVs, while the oligosaccharide importer SusC remains mostly in the OM. We found that all OMV-enriched lipoproteins possess a lipoprotein export sequence (LES), and we show that this signal mediates translocation of SusG from the periplasmic face of the OM toward the extracellular milieu. Mutations in the LES motif caused defects in surface exposure and recruitment of SusG into OMVs. These experiments link, for the first time, surface exposure to recruitment of proteins into OMVs. We also show that surface-exposed SusG in OMVs is active and rescues the growth of bacterial cells incapable of growing on starch as the only carbon source. Our results support the role of OMVs as “public goods” that can be utilized by other organisms with different metabolic capabilities. IMPORTANCE Species from the Bacteroides genus are predominant members of the human gut microbiota. OMVs in Bacteroides have been shown to be important for the homeostasis of complex host-commensal relationships, mainly involving immune tolerance and protection from disease. OMVs carry many enzymatic activities involved in the cleavage of complex polysaccharides and have been proposed as public goods that can provide growth to other bacterial species by release of polysaccharide breakdown products into the gut lumen. This work shows that the presence of a negatively charged rich amino acid motif (LES) is required for efficient packing of the surface-exposed alpha-amylase SusG into OMVs. Our findings strongly suggest that surface exposure is coupled to packing of Bacteroides lipoproteins into OMVs. This is the first step in the generation of tailor-made probiotic interventions that can exploit LES-related sequences to generate Bacteroides strains displaying proteins of interest in OMVs.
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Pedrogo DAM, Jensen MD, Van Dyke CT, Murray JA, Woods JA, Chen J, Kashyap PC, Nehra V. Gut Microbial Carbohydrate Metabolism Hinders Weight Loss in Overweight Adults Undergoing Lifestyle Intervention With a Volumetric Diet. Mayo Clin Proc 2018; 93:1104-1110. [PMID: 30077203 PMCID: PMC6107068 DOI: 10.1016/j.mayocp.2018.02.019] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 02/09/2018] [Accepted: 02/23/2018] [Indexed: 01/31/2023]
Abstract
The rising incidence of obesity requires the reevaluation of our current therapeutic strategies to optimize patient outcomes. The objective of this study was to determine whether compositional and functional characteristics of the gut microbiota in adults predict responses to a comprehensive lifestyle intervention program in overweight and obese adults. We recruited 26 participants from the Mayo Clinic Obesity Treatment Research Program between August 6, 2013, and September 12, 2013, to participate in a lifestyle intervention program for weight loss. Adults aged 18 to 65 years with a body mass index of 27 to 39.9 kg/m2 and able to provide informed consent were included in the study. Fecal stool samples were obtained at baseline and after 3 months. Loss of at least 5% of baseline weight after 3 months was defined as success. Clinical characteristics and gut microbial composition and function were compared between those who achieved at least 5% and those who achieved less than 5% weight loss. After 3 months, 9 of 26 participants lost at least 5% of their weight. The mean weight loss was 7.89 kg (95% CI, 6.46-9.32 kg) in the success group and 1.51 kg (95% CI, 0.52-2.49 kg) in the less than 5% weight loss group. An increased abundance of Phascolarctobacterium was associated with success. In contrast, an increased abundance of Dialister and of genes encoding gut microbial carbohydrate-active enzymes was associated with failure to lose 5% body weight. A gut microbiota with increased capability for carbohydrate metabolism appears to be associated with decreased weight loss in overweight and obese patients undergoing a lifestyle intervention program.
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Affiliation(s)
- David A. Muñiz Pedrogo
- Center for Clinical and Translational Science, Mayo Clinic, Rochester, MN
- University of Puerto Rico School of Medicine, San Juan, Puerto Rico
| | - Michael D. Jensen
- Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic, Rochester, MN
| | - Carol T. Van Dyke
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN
| | - Joseph A. Murray
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN
| | - Jeffrey A. Woods
- Professor of Kinesiology and Community Health; Director, Center on Health, Aging and Disability. University of Illinois at Urbana-Champaign, Champaign, IL
| | - Jun Chen
- Department of Health Sciences Research, Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, USA
| | - Purna C. Kashyap
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN
- Corresponding authors: Purna Kashyap, MBBS, Assistant Professor of Medicine, Vandana Nehra, MD, Assistant professor of Medicine, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN. 55905, and
| | - Vandana Nehra
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN
- Corresponding authors: Purna Kashyap, MBBS, Assistant Professor of Medicine, Vandana Nehra, MD, Assistant professor of Medicine, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN. 55905, and
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44
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Tuson HH, Foley MH, Koropatkin NM, Biteen JS. The Starch Utilization System Assembles around Stationary Starch-Binding Proteins. Biophys J 2018; 115:242-250. [PMID: 29338841 PMCID: PMC6051301 DOI: 10.1016/j.bpj.2017.12.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 12/02/2017] [Accepted: 12/11/2017] [Indexed: 02/08/2023] Open
Abstract
Bacteroides thetaiotaomicron (Bt) is a prominent member of the human gut microbiota with an extensive capacity for glycan harvest. This bacterium expresses a five-protein complex in the outer membrane, called the starch utilization system (Sus), which binds, degrades, and imports starch into the cell. Sus is a model system for the many glycan-targeting polysaccharide utilization loci found in Bt and other members of the Bacteroidetes phylum. Our previous work has shown that SusG, a lipidated amylase in the outer membrane, explores the entire cell surface but diffuses more slowly as it interacts with starch. Here, we use a combination of single-molecule tracking, super-resolution imaging, reverse genetics, and proteomics to show that SusE and SusF, two proteins that bind starch, are immobile on the cell surface even when other members of the system are knocked out and under multiple different growth conditions. This observation suggests a new paradigm for protein complex formation: binding proteins form immobile complexes that transiently associate with a mobile enzyme partner.
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Affiliation(s)
- Hannah H Tuson
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan
| | - Matthew H Foley
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan.
| | - Julie S Biteen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan.
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45
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Arnal G, Cockburn DW, Brumer H, Koropatkin NM. Structural basis for the flexible recognition of α-glucan substrates by Bacteroides thetaiotaomicron SusG. Protein Sci 2018; 27:1093-1101. [PMID: 29603462 PMCID: PMC5980535 DOI: 10.1002/pro.3410] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 03/15/2018] [Accepted: 03/21/2018] [Indexed: 11/09/2022]
Abstract
Bacteria that reside in the mammalian intestinal tract efficiently hydrolyze dietary carbohydrates, including starch, that escape digestion in the small intestine. Starch is an abundant dietary carbohydrate comprised of α1,4 and α1,6 linked glucose, yet mammalian intestinal glucoamylases cannot effectively hydrolyze starch that has frequent α1,6 branching as these structures hinder recognition and processing by α1,4-specific amylases. Here we present the structure of the cell surface amylase SusG from Bacteroides thetaiotaomicron complexed with a mixed linkage amylosaccharide generated from transglycosylation during crystallization. Although SusG is specific for α1,4 glucosidic bonds, binding of this new oligosaccharide at the active site demonstrates that SusG can accommodate α1,6 branch points at subsite -3 to -2, and also at subsite+1 adjacent to the site of hydrolysis, explaining how this enzyme may be able to process a wide range of limit dextrins in the intestinal environment. These data suggest that B. thetaiotaomicron and related organisms may have a selective advantage for amylosaccharide scavenging in the gut.
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Affiliation(s)
- Gregory Arnal
- Michael Smith Laboratories, University of British Columbia, 2185 East MallVancouverBritish ColumbiaV6T 1Z4Canada
| | - Darrell W. Cockburn
- Department of Microbiology and ImmunologyUniversity of Michigan Medical School, 1150 W Medical Center DriveAnn ArborMichigan
- Present address:
Department of Food SciencePennsylvania State UniversityUniversity ParkPennsylvania
| | - Harry Brumer
- Michael Smith Laboratories, University of British Columbia, 2185 East MallVancouverBritish ColumbiaV6T 1Z4Canada
- Department of ChemistryUniversity of British Columbia, 2036 Main MallVancouverBritish ColumbiaV6T 1Z1Canada
- Department of Biochemistry and Molecular BiologyUniversity of British Columbia, 2350 Health Sciences MallVancouverBritish ColumbiaV6T 1Z3Canada
| | - Nicole M. Koropatkin
- Department of Microbiology and ImmunologyUniversity of Michigan Medical School, 1150 W Medical Center DriveAnn ArborMichigan
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46
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Foley MH, Martens EC, Koropatkin NM. SusE facilitates starch uptake independent of starch binding in B. thetaiotaomicron. Mol Microbiol 2018; 108:551-566. [PMID: 29528148 PMCID: PMC5980745 DOI: 10.1111/mmi.13949] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2018] [Indexed: 12/30/2022]
Abstract
The Bacteroides thetaiotaomicron starch utilization system (Sus) is a model system for nutrient acquisition by gut Bacteroidetes, a dominant phylum of gut bacteria. The Sus includes SusCDEFG, which assemble on the cell surface to capture, degrade and import starch. While SusD is an essential starch-binding protein, the precise role(s) of the partially homologous starch-binding proteins SusE and SusF has remained elusive. We previously reported that a non-binding version of SusD (SusD*) supports growth on starch when other members of the multi-protein complex are present. Here we demonstrate that SusE supports SusD* growth on maltooligosaccharides, and determine the domains of SusE essential for this function. Furthermore, we demonstrate that SusE does not need to bind starch to support growth in the presence of SusD*, suggesting that the assembly of SusCDE is most important for maltooligosaccharide uptake in this context. However, starch binding by proteins SusDEF directs the uptake of maltooligosaccharides of specific lengths, suggesting that these proteins equip the cell to scavenge a range of starch fragments. These data demonstrate that the assembly of core Sus proteins SusCDE is secondary to their glycan binding roles, but glycan binding by Sus proteins may fine tune the selection of glycans from the environment.
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Affiliation(s)
- Matthew H. Foley
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Eric C. Martens
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Nicole M. Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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47
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Santilli AD, Dawson EM, Whitehead KJ, Whitehead DC. Nonmicrobicidal Small Molecule Inhibition of Polysaccharide Metabolism in Human Gut Microbes: A Potential Therapeutic Avenue. ACS Chem Biol 2018; 13:1165-1172. [PMID: 29660284 DOI: 10.1021/acschembio.8b00309] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A new approach for the nonmicrobicidal phenotypic manipulation of prominent gastrointestinal microbes is presented. Low micromolar concentrations of a chemical probe, acarbose, can selectively inhibit the Starch Utilization System and ablate the ability of Bacteroides thetaiotaomicron and B. fragilis strains to metabolize potato starch and pullulan. This strategy has potential therapeutic relevance for the selective modulation of the GI microbiota in a nonmicrobicidal manner.
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Affiliation(s)
- Anthony D. Santilli
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634, United States
| | - Elizabeth M. Dawson
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634, United States
| | - Kristi J. Whitehead
- Department of Biological Sciences, Clemson University, Clemson, South Carolina 29634, United States
| | - Daniel C. Whitehead
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634, United States
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48
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The Importance of Surface-Binding Site towards Starch-Adsorptivity Level in α-Amylase: A Review on Structural Point of View. Enzyme Res 2017; 2017:4086845. [PMID: 29359041 PMCID: PMC5735674 DOI: 10.1155/2017/4086845] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Accepted: 10/31/2017] [Indexed: 12/04/2022] Open
Abstract
Starch is a polymeric carbohydrate composed of glucose. As a source of energy, starch can be degraded by various amylolytic enzymes, including α-amylase. In a large-scale industry, starch processing cost is still expensive due to the requirement of high temperature during the gelatinization step. Therefore, α-amylase with raw starch digesting ability could decrease the energy cost by avoiding the high gelatinization temperature. It is known that the carbohydrate-binding module (CBM) and the surface-binding site (SBS) of α-amylase could facilitate the substrate binding to the enzyme's active site to enhance the starch digestion. These sites are a noncatalytic module, which could interact with a lengthy substrate such as insoluble starch. The major interaction between these sites and the substrate is the CH/pi-stacking interaction with the glucose ring. Several mutation studies on the Halothermothrix orenii, SusG Bacteroides thetaiotamicron, Barley, Aspergillus niger, and Saccharomycopsis fibuligera α-amylases have revealed that the stacking interaction through the aromatic residues at the SBS is essential to the starch adsorption. In this review, the SBS in various α-amylases is also presented. Therefore, based on the structural point of view, SBS is suggested as an essential site in α-amylase to increase its catalytic activity, especially towards the insoluble starch.
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49
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Navigating the Gut Buffet: Control of Polysaccharide Utilization in Bacteroides spp. Trends Microbiol 2017; 25:1005-1015. [DOI: 10.1016/j.tim.2017.06.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 06/09/2017] [Accepted: 06/20/2017] [Indexed: 12/26/2022]
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50
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Yusuf *M, Baroroh *U, Hasan K, Rachman SD, Ishmayana S, Subroto T. Computational Model of the Effect of a Surface-Binding Site on the Saccharomycopsis fibuligera R64 α-Amylase to the Substrate Adsorption. Bioinform Biol Insights 2017; 11:1177932217738764. [PMID: 29162975 PMCID: PMC5676498 DOI: 10.1177/1177932217738764] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 09/16/2017] [Indexed: 11/15/2022] Open
Abstract
α-Amylase is one of the important enzymes in the starch-processing industry. However, starch processing requires high temperature, thus resulting in high cost. The high adsorptivity of α-amylase to the substrate allows this enzyme to digest the starch at a lower temperature. α-Amylase from Saccharomycopsis fibuligera R64 (Sfamy R64), a locally sourced enzyme from Indonesia, has a high amylolytic activity but low starch adsorptivity. The objective of this study was to design a computational model of Sfamy R64 with increased starch adsorptivity using bioinformatics method. The model structure of Sfamy R64 was compared with the positive control, ie, Aspergillus niger α-amylase. The structural comparison showed that Sfamy R64 lacks the surface-binding site (SBS). An SBS was introduced to the structure of Sfamy R64 by S383Y/S386W mutations. The dynamics and binding affinity of the SBS of mutant to the substrate were also improved and comparable with that of the positive control.
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Affiliation(s)
- *Muhammad Yusuf
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang, Indonesia
- Research Center of Molecular Biotechnology and Bioinformatics, Universitas Padjadjaran, Bandung, Indonesia
| | - *Umi Baroroh
- Master of Biotechnology Program, Postgraduate School, Universitas Padjadjaran, Bandung, Indonesia
| | - Khomaini Hasan
- Faculty of Medicine, Universitas Jenderal Achmad Yani, Cimahi, Indonesia
| | - Saadah Diana Rachman
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang, Indonesia
| | - Safri Ishmayana
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang, Indonesia
| | - Toto Subroto
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Sumedang, Indonesia
- Research Center of Molecular Biotechnology and Bioinformatics, Universitas Padjadjaran, Bandung, Indonesia
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