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Wang X, Jiang Y, Liu H, Zhang X, Yuan H, Huang D, Wang T. In vitro assembly of the trehalose bi-enzyme complex with artificial scaffold protein. Front Bioeng Biotechnol 2023; 11:1251298. [PMID: 37711449 PMCID: PMC10497880 DOI: 10.3389/fbioe.2023.1251298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 08/15/2023] [Indexed: 09/16/2023] Open
Abstract
Introduction: Trehalose is a significant rare sugar known for its stable properties and ability to protect biomolecules from environmental factors. Methods: In this study, we present a novel approach utilizing a scaffold protein-mediated assembly method for the formation of a trehalose bi-enzyme complex. This complex consists of maltooligosyltrehalose synthase (MTSase) and maltooligosyltrehalose trehalohydrolase (MTHase), which work in tandem to catalyze the substrate and enhance the overall catalytic efficiency. Utilizing the specific interaction between cohesin and dockerin, this study presents the implementation of an assembly, an analysis of its efficiency, and an exploration of strategies to enhance enzyme utilization through the construction of a bi-enzyme complex under optimal conditions in vitro. Results and Discussion: The bi-enzyme complex demonstrated a trehalose production level 1.5 times higher than that of the free enzyme mixture at 40 h, with a sustained upward trend. Compared to free enzyme mixtures, the adoption of a scaffold protein-mediated bi-enzyme complex may improve cascade reactions and catalytic effects, thus presenting promising prospects.
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Affiliation(s)
- Xiangyi Wang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Shandong Academy of Sciences, Qilu University of Technology, Jinan, Shandong, China
- Key Laboratory of Shandong Microbial Engineering, School of Bioengineering, Shandong Academy of Sciences, Qilu University of Technology, Jinan, Shandong, China
| | - Yi Jiang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Shandong Academy of Sciences, Qilu University of Technology, Jinan, Shandong, China
- Key Laboratory of Shandong Microbial Engineering, School of Bioengineering, Shandong Academy of Sciences, Qilu University of Technology, Jinan, Shandong, China
| | - Hongling Liu
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Shandong Academy of Sciences, Qilu University of Technology, Jinan, Shandong, China
- Key Laboratory of Shandong Microbial Engineering, School of Bioengineering, Shandong Academy of Sciences, Qilu University of Technology, Jinan, Shandong, China
| | - Xinyi Zhang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Shandong Academy of Sciences, Qilu University of Technology, Jinan, Shandong, China
- Key Laboratory of Shandong Microbial Engineering, School of Bioengineering, Shandong Academy of Sciences, Qilu University of Technology, Jinan, Shandong, China
| | - Haibo Yuan
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Shandong Academy of Sciences, Qilu University of Technology, Jinan, Shandong, China
- Key Laboratory of Shandong Microbial Engineering, School of Bioengineering, Shandong Academy of Sciences, Qilu University of Technology, Jinan, Shandong, China
| | - Di Huang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Shandong Academy of Sciences, Qilu University of Technology, Jinan, Shandong, China
- Key Laboratory of Shandong Microbial Engineering, School of Bioengineering, Shandong Academy of Sciences, Qilu University of Technology, Jinan, Shandong, China
| | - Tengfei Wang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Shandong Academy of Sciences, Qilu University of Technology, Jinan, Shandong, China
- Key Laboratory of Shandong Microbial Engineering, School of Bioengineering, Shandong Academy of Sciences, Qilu University of Technology, Jinan, Shandong, China
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2
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Cabral L, Persinoti GF, Paixão DAA, Martins MP, Morais MAB, Chinaglia M, Domingues MN, Sforca ML, Pirolla RAS, Generoso WC, Santos CA, Maciel LF, Terrapon N, Lombard V, Henrissat B, Murakami MT. Gut microbiome of the largest living rodent harbors unprecedented enzymatic systems to degrade plant polysaccharides. Nat Commun 2022; 13:629. [PMID: 35110564 PMCID: PMC8810776 DOI: 10.1038/s41467-022-28310-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 01/14/2022] [Indexed: 12/12/2022] Open
Abstract
The largest living rodent, capybara, can efficiently depolymerize and utilize lignocellulosic biomass through microbial symbiotic mechanisms yet elusive. Herein, we elucidate the microbial community composition, enzymatic systems and metabolic pathways involved in the conversion of dietary fibers into short-chain fatty acids, a main energy source for the host. In this microbiota, the unconventional enzymatic machinery from Fibrobacteres seems to drive cellulose degradation, whereas a diverse set of carbohydrate-active enzymes from Bacteroidetes, organized in polysaccharide utilization loci, are accounted to tackle complex hemicelluloses typically found in gramineous and aquatic plants. Exploring the genetic potential of this community, we discover a glycoside hydrolase family of β-galactosidases (named as GH173), and a carbohydrate-binding module family (named as CBM89) involved in xylan binding that establishes an unprecedented three-dimensional fold among associated modules to carbohydrate-active enzymes. Together, these results demonstrate how the capybara gut microbiota orchestrates the depolymerization and utilization of plant fibers, representing an untapped reservoir of enzymatic mechanisms to overcome the lignocellulose recalcitrance, a central challenge toward a sustainable and bio-based economy. Here, Cabral et al., perform a multi-omics analysis of the gut microbiome of capybara, the largest living rodent, unveiling enzymatic mechanisms for the breakdown of lignocellulosic biomass, and report two undescribed families of carbohydrate-active enzymes.
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Affiliation(s)
- Lucelia Cabral
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil
| | - Gabriela F Persinoti
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil.
| | - Douglas A A Paixão
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil
| | - Marcele P Martins
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil.,Graduate Program in Functional and Molecular Biology, Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - Mariana A B Morais
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil
| | - Mariana Chinaglia
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil.,Graduate Program in Functional and Molecular Biology, Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - Mariane N Domingues
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil
| | - Mauricio L Sforca
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil
| | - Renan A S Pirolla
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil
| | - Wesley C Generoso
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil
| | - Clelton A Santos
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil
| | - Lucas F Maciel
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil
| | - Nicolas Terrapon
- The Institut National de la Recherche Agronomique, USC 1408 AFMB, 13288, Marseille, France.,Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, Marseille, France
| | - Vincent Lombard
- The Institut National de la Recherche Agronomique, USC 1408 AFMB, 13288, Marseille, France.,Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, Marseille, France
| | - Bernard Henrissat
- Department of Biotechnology and Biomedicine (DTU Bioengineering), Technical University of Denmark, 2800 Kgs, Lyngby, Denmark.,Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mario T Murakami
- Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil.
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3
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Research progress and the biotechnological applications of multienzyme complex. Appl Microbiol Biotechnol 2021; 105:1759-1777. [PMID: 33564922 DOI: 10.1007/s00253-021-11121-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 01/07/2021] [Accepted: 01/16/2021] [Indexed: 11/26/2022]
Abstract
The multienzyme complex system has become a research focus in synthetic biology due to its highly efficient overall catalytic ability and has been applied to various fields. Multienzyme complexes are formed by cascading complexes, which are multiple functionally related enzymes that continuously and efficiently catalyze the production of substrates. Compared with current mainstream microbial cell catalytic systems, in vitro multienzyme molecular machines have many advantages, such as fewer side reactions, a high product yield, a fast reaction speed, easy product separation, a tolerable toxic environment, and robust system operability, showing increasing competitiveness in the field of biomanufacturing. In this review, the research progress of multienzyme complexes in nature and multienzyme cascades in vivo or in vitro will be introduced, and the discovered enzyme cascades concerning scaffolding proteins will also be discussed. This review is expected to provide a more theoretical basis for the modification of multienzyme complexes and broaden their application in the field of synthetic biology. KEY POINTS: • The cascade reactions of some natural multienzyme complexes are reviewed. • The main approaches of constructing artificial multienzyme complexes are summarized. • The structure and application of cellulosomes are discussed and prospected.
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4
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Bule P, Pires VMR, Alves VD, Carvalho AL, Prates JAM, Ferreira LMA, Smith SP, Gilbert HJ, Noach I, Bayer EA, Najmudin S, Fontes CMGA. Higher order scaffoldin assembly in Ruminococcus flavefaciens cellulosome is coordinated by a discrete cohesin-dockerin interaction. Sci Rep 2018; 8:6987. [PMID: 29725056 PMCID: PMC5934362 DOI: 10.1038/s41598-018-25171-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/17/2018] [Indexed: 12/25/2022] Open
Abstract
Cellulosomes are highly sophisticated molecular nanomachines that participate in the deconstruction of complex polysaccharides, notably cellulose and hemicellulose. Cellulosomal assembly is orchestrated by the interaction of enzyme-borne dockerin (Doc) modules to tandem cohesin (Coh) modules of a non-catalytic primary scaffoldin. In some cases, as exemplified by the cellulosome of the major cellulolytic ruminal bacterium Ruminococcus flavefaciens, primary scaffoldins bind to adaptor scaffoldins that further interact with the cell surface via anchoring scaffoldins, thereby increasing cellulosome complexity. Here we elucidate the structure of the unique Doc of R. flavefaciens FD-1 primary scaffoldin ScaA, bound to Coh 5 of the adaptor scaffoldin ScaB. The RfCohScaB5-DocScaA complex has an elliptical architecture similar to previously described complexes from a variety of ecological niches. ScaA Doc presents a single-binding mode, analogous to that described for the other two Coh-Doc specificities required for cellulosome assembly in R. flavefaciens. The exclusive reliance on a single-mode of Coh recognition contrasts with the majority of cellulosomes from other bacterial species described to date, where Docs contain two similar Coh-binding interfaces promoting a dual-binding mode. The discrete Coh-Doc interactions observed in ruminal cellulosomes suggest an adaptation to the exquisite properties of the rumen environment.
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Affiliation(s)
- Pedro Bule
- CIISA - Faculdade de Medicina Veterinária, ULisboa, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477, Lisboa, Portugal.
| | - Virgínia M R Pires
- CIISA - Faculdade de Medicina Veterinária, ULisboa, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477, Lisboa, Portugal
| | - Victor D Alves
- CIISA - Faculdade de Medicina Veterinária, ULisboa, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477, Lisboa, Portugal
| | - Ana Luísa Carvalho
- UCIBIO-REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
| | - José A M Prates
- CIISA - Faculdade de Medicina Veterinária, ULisboa, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477, Lisboa, Portugal
| | - Luís M A Ferreira
- CIISA - Faculdade de Medicina Veterinária, ULisboa, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477, Lisboa, Portugal
| | - Steven P Smith
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Harry J Gilbert
- Institute for Cell and Molecular Biosciences, Newcastle University, The Medical School, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Ilit Noach
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Edward A Bayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Shabir Najmudin
- CIISA - Faculdade de Medicina Veterinária, ULisboa, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477, Lisboa, Portugal
| | - Carlos M G A Fontes
- CIISA - Faculdade de Medicina Veterinária, ULisboa, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477, Lisboa, Portugal. .,NZYTech genes & enzymes, Estrada do Paço do Lumiar, 1649-038, Lisboa, Portugal.
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5
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Israeli-Ruimy V, Bule P, Jindou S, Dassa B, Moraïs S, Borovok I, Barak Y, Slutzki M, Hamberg Y, Cardoso V, Alves VD, Najmudin S, White BA, Flint HJ, Gilbert HJ, Lamed R, Fontes CMGA, Bayer EA. Complexity of the Ruminococcus flavefaciens FD-1 cellulosome reflects an expansion of family-related protein-protein interactions. Sci Rep 2017; 7:42355. [PMID: 28186207 PMCID: PMC5301203 DOI: 10.1038/srep42355] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 01/08/2017] [Indexed: 11/25/2022] Open
Abstract
Protein-protein interactions play a vital role in cellular processes as exemplified by assembly of the intricate multi-enzyme cellulosome complex. Cellulosomes are assembled by selective high-affinity binding of enzyme-borne dockerin modules to repeated cohesin modules of structural proteins termed scaffoldins. Recent sequencing of the fiber-degrading Ruminococcus flavefaciens FD-1 genome revealed a particularly elaborate cellulosome system. In total, 223 dockerin-bearing ORFs potentially involved in cellulosome assembly and a variety of multi-modular scaffoldins were identified, and the dockerins were classified into six major groups. Here, extensive screening employing three complementary medium- to high-throughput platforms was used to characterize the different cohesin-dockerin specificities. The platforms included (i) cellulose-coated microarray assay, (ii) enzyme-linked immunosorbent assay (ELISA) and (iii) in-vivo co-expression and screening in Escherichia coli. The data revealed a collection of unique cohesin-dockerin interactions and support the functional relevance of dockerin classification into groups. In contrast to observations reported previously, a dual-binding mode is involved in cellulosome cell-surface attachment, whereas single-binding interactions operate for cellulosome integration of enzymes. This sui generis cellulosome model enhances our understanding of the mechanisms governing the remarkable ability of R. flavefaciens to degrade carbohydrates in the bovine rumen and provides a basis for constructing efficient nano-machines applied to biological processes.
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Affiliation(s)
- Vered Israeli-Ruimy
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Pedro Bule
- CIISA – Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Sadanari Jindou
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Bareket Dassa
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Sarah Moraïs
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Yoav Barak
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
- Chemical Research Support, The Weizmann Institute of Science, Rehovot, Israel
| | - Michal Slutzki
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Yuval Hamberg
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Vânia Cardoso
- CIISA – Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Victor D. Alves
- CIISA – Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Shabir Najmudin
- CIISA – Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Bryan A. White
- Department of Animal Sciences, Institute for Genomic Biology, University of Illinois at Urbana–Champaign, Champaign, IL, USA
- Department of Animal Sciences, University of Illinois at Urbana–Champaign, Champaign, IL, USA
| | - Harry J. Flint
- Microbiology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Foresterhill, Aberdeen, Scotland, UK
| | - Harry J. Gilbert
- Institute for Cell and Molecular Biosciences, Newcastle University, The Medical School, Newcastle upon Tyne NE2 4HH, UK
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Carlos M. G. A. Fontes
- CIISA – Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Edward A. Bayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
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6
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Bensoussan L, Moraïs S, Dassa B, Friedman N, Henrissat B, Lombard V, Bayer EA, Mizrahi I. Broad phylogeny and functionality of cellulosomal components in the bovine rumen microbiome. Environ Microbiol 2016; 19:185-197. [PMID: 27712009 PMCID: PMC6487960 DOI: 10.1111/1462-2920.13561] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 09/29/2016] [Indexed: 11/30/2022]
Abstract
The cellulosome is an extracellular multi‐enzyme complex that is considered one of the most efficient plant cell wall‐degrading strategies devised by nature. Its unique modular architecture, achieved by high affinity and specific interaction between protein modules (cohesins and dockerins) enables formation of various enzyme combinations. Extensive research has been dedicated to the mechanistic nature of the cellulosome complex. Nevertheless, little is known regarding its distribution and abundance among microbes in natural plant fibre‐rich environments. Here, we explored these questions in bovine rumen microbial communities, specialized in efficient degradation of lignocellulosic plant material. We bioinformatically screened for cellulosomal modules in this complex environment using a previously published ultra‐deep fibre‐adherent rumen metagenome. Intriguingly, a large portion of the functions of the dockerin‐containing proteins were related to alternative biological processes, and not necessarily to the classic fibre degradation function. Our analysis was experimentally validated by characterizing specific interactions between selected cohesins and dockerins and revealed that cellulosome is a more generalized strategy used by diverse bacteria, some of which were not previously associated with cellulosome production. Remarkably, our results provide additional proof of similarity among rumen microbial communities worldwide. This study suggests a broader and widespread role for the cellulosomal machinery in nature.
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Affiliation(s)
- Lizi Bensoussan
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Sarah Moraïs
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Bareket Dassa
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Nir Friedman
- The Faculty of Natural Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, UMR6098, Aix-Marseille University, CNRS UMR7257, Marseille, France
| | - Vincent Lombard
- Architecture et Fonction des Macromolécules Biologiques, UMR6098, Aix-Marseille University, CNRS UMR7257, Marseille, France
| | - Edward A Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Itzhak Mizrahi
- The Faculty of Natural Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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7
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Gunnoo M, Cazade PA, Galera-Prat A, Nash MA, Czjzek M, Cieplak M, Alvarez B, Aguilar M, Karpol A, Gaub H, Carrión-Vázquez M, Bayer EA, Thompson D. Nanoscale Engineering of Designer Cellulosomes. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:5619-47. [PMID: 26748482 DOI: 10.1002/adma.201503948] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 10/01/2015] [Indexed: 05/27/2023]
Abstract
Biocatalysts showcase the upper limit obtainable for high-speed molecular processing and transformation. Efforts to engineer functionality in synthetic nanostructured materials are guided by the increasing knowledge of evolving architectures, which enable controlled molecular motion and precise molecular recognition. The cellulosome is a biological nanomachine, which, as a fundamental component of the plant-digestion machinery from bacterial cells, has a key potential role in the successful development of environmentally-friendly processes to produce biofuels and fine chemicals from the breakdown of biomass waste. Here, the progress toward so-called "designer cellulosomes", which provide an elegant alternative to enzyme cocktails for lignocellulose breakdown, is reviewed. Particular attention is paid to rational design via computational modeling coupled with nanoscale characterization and engineering tools. Remaining challenges and potential routes to industrial application are put forward.
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Affiliation(s)
- Melissabye Gunnoo
- Materials and Surface Science Institute and Department of Physics and Energy, University of Limerick, Limerick, Ireland
| | - Pierre-André Cazade
- Materials and Surface Science Institute and Department of Physics and Energy, University of Limerick, Limerick, Ireland
| | - Albert Galera-Prat
- Instituto Cajal, Consejo Superior de Investigaciones Cientificas (CSIC), IMDEA Nanociencias and CIBERNED, Madrid, Spain
| | - Michael A Nash
- Lehrstuhl für Angewandte Physik and Center for Nanoscience, Ludwig-Maximilians-University, 80799, Munich, Germany
| | - Mirjam Czjzek
- Sorbonne Universités, UPMC, Université Paris 06, and Centre National de la Recherche Scientifique, UMR 8227, Integrative Biology of Marine Models, Station Biologique, de Roscoff, CS 90074, F-29688, Roscoff cedex, Bretagne, France
| | - Marek Cieplak
- Laboratory of Biological Physics, Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
| | - Beatriz Alvarez
- Biopolis S.L., Parc Científic de la Universitat de Valencia, Edificio 2, C/Catedrático Agustín Escardino 9, 46980, Paterna (Valencia), Spain
| | - Marina Aguilar
- Abengoa, S.A., Palmas Altas, Calle Energía Solar nº 1, 41014, Seville, Spain
| | - Alon Karpol
- Designer Energy Ltd., 2 Bergman St., Tamar Science Park, Rehovot, 7670504, Israel
| | - Hermann Gaub
- Lehrstuhl für Angewandte Physik and Center for Nanoscience, Ludwig-Maximilians-University, 80799, Munich, Germany
| | - Mariano Carrión-Vázquez
- Instituto Cajal, Consejo Superior de Investigaciones Cientificas (CSIC), IMDEA Nanociencias and CIBERNED, Madrid, Spain
| | - Edward A Bayer
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Damien Thompson
- Materials and Surface Science Institute and Department of Physics and Energy, University of Limerick, Limerick, Ireland
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8
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Moraïs S, Ben David Y, Bensoussan L, Duncan SH, Koropatkin NM, Martens EC, Flint HJ, Bayer EA. Enzymatic profiling of cellulosomal enzymes from the human gut bacterium, Ruminococcus champanellensis, reveals a fine-tuned system for cohesin-dockerin recognition. Environ Microbiol 2016; 18:542-56. [PMID: 26347002 DOI: 10.1111/1462-2920.13047] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/02/2015] [Accepted: 09/02/2015] [Indexed: 12/16/2023]
Abstract
Ruminococcus champanellensis is considered a keystone species in the human gut that degrades microcrystalline cellulose efficiently and contains the genetic elements necessary for cellulosome production. The basic elements of its cellulosome architecture, mainly cohesin and dockerin modules from scaffoldins and enzyme-borne dockerins, have been characterized recently. In this study, we cloned, expressed and characterized all of the glycoside hydrolases that contain a dockerin module. Among the 25 enzymes, 10 cellulases, 4 xylanases, 3 mannanases, 2 xyloglucanases, 2 arabinofuranosidases, 2 arabinanases and one β-glucanase were assessed for their comparative enzymatic activity on their respective substrates. The dockerin specificities of the enzymes were examined by ELISA, and 80 positives out of 525 possible interactions were detected. Our analysis reveals a fine-tuned system for cohesin-dockerin specificity and the importance of diversity among the cohesin-dockerin sequences. Our results imply that cohesin-dockerin pairs are not necessarily assembled at random among the same specificity types, as generally believed for other cellulosome-producing bacteria, but reveal a more organized cellulosome architecture. Moreover, our results highlight the importance of the cellulosome paradigm for cellulose and hemicellulose degradation by R. champanellensis in the human gut.
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Affiliation(s)
- Sarah Moraïs
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Yonit Ben David
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Lizi Bensoussan
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Sylvia H Duncan
- Microbiology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
| | - Nicole M Koropatkin
- 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
| | - Harry J Flint
- Microbiology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
| | - Edward A Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
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9
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Unique Organization of Extracellular Amylases into Amylosomes in the Resistant Starch-Utilizing Human Colonic Firmicutes Bacterium Ruminococcus bromii. mBio 2015; 6:e01058-15. [PMID: 26419877 PMCID: PMC4611034 DOI: 10.1128/mbio.01058-15] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
UNLABELLED Ruminococcus bromii is a dominant member of the human gut microbiota that plays a key role in releasing energy from dietary starches that escape digestion by host enzymes via its exceptional activity against particulate "resistant" starches. Genomic analysis of R. bromii shows that it is highly specialized, with 15 of its 21 glycoside hydrolases belonging to one family (GH13). We found that amylase activity in R. bromii is expressed constitutively, with the activity seen during growth with fructose as an energy source being similar to that seen with starch as an energy source. Six GH13 amylases that carry signal peptides were detected by proteomic analysis in R. bromii cultures. Four of these enzymes are among 26 R. bromii proteins predicted to carry dockerin modules, with one, Amy4, also carrying a cohesin module. Since cohesin-dockerin interactions are known to mediate the formation of protein complexes in cellulolytic ruminococci, the binding interactions of four cohesins and 11 dockerins from R. bromii were investigated after overexpressing them as recombinant fusion proteins. Dockerins possessed by the enzymes Amy4 and Amy9 are predicted to bind a cohesin present in protein scaffoldin 2 (Sca2), which resembles the ScaE cell wall-anchoring protein of a cellulolytic relative, R. flavefaciens. Further complexes are predicted between the dockerin-carrying amylases Amy4, Amy9, Amy10, and Amy12 and two other cohesin-carrying proteins, while Amy4 has the ability to autoaggregate, as its dockerin can recognize its own cohesin. This organization of starch-degrading enzymes is unprecedented and provides the first example of cohesin-dockerin interactions being involved in an amylolytic system, which we refer to as an "amylosome." IMPORTANCE Fermentation of dietary nondigestible carbohydrates by the human colonic microbiota supplies much of the energy that supports microbial growth in the intestine. This activity has important consequences for health via modulation of microbiota composition and the physiological and nutritional effects of microbial metabolites, including the supply of energy to the host from short-chain fatty acids. Recent evidence indicates that certain human colonic bacteria play keystone roles in degrading nondigestible substrates, with the dominant but little-studied species Ruminococcus bromii displaying an exceptional ability to degrade dietary resistant starches (i.e., dietary starches that escape digestion by host enzymes in the upper gastrointestinal tract because of protection provided by other polymers, particle structure, retrogradation, or chemical cross-linking). In this report, we reveal the unique organization of the amylolytic enzyme system of R. bromii that involves cohesin-dockerin interactions between component proteins. While dockerins and cohesins are fundamental to the organization of cellulosomal enzyme systems of cellulolytic ruminococci, their contribution to organization of amylases has not previously been recognized and may help to explain the starch-degrading abilities of R. bromii.
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Weinstein JY, Slutzki M, Karpol A, Barak Y, Gul O, Lamed R, Bayer EA, Fried DB. Insights into a type III cohesin-dockerin recognition interface from the cellulose-degrading bacterium Ruminococcus flavefaciens. J Mol Recognit 2015; 28:148-54. [PMID: 25639797 DOI: 10.1002/jmr.2380] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 04/08/2014] [Accepted: 04/08/2014] [Indexed: 11/09/2022]
Abstract
Cellulosomes are large multicomponent cellulose-degrading assemblies found on the surfaces of cellulolytic microorganisms. Often containing hundreds of components, the self-assembly of cellulosomes is mediated by the ultra-high-affinity cohesin-dockerin interaction, which allows them to adopt the complex architectures necessary for degrading recalcitrant cellulose. Better understanding of how the cellulosome assembles and functions and what kinds of structures it adopts will further effort to develop industrial applications of cellulosome components, including their use in bioenergy production. Ruminococcus flavefaciens is a well-studied anaerobic cellulolytic bacteria found in the intestinal tracts of ruminants and other herbivores. Key to cellulosomal self-assembly in this bacterium is the dockerin ScaADoc, found on the non-catalytic structural subunit scaffoldin ScaA, which is responsible for assembling arrays of cellulose-degrading enzymes. This work expands on previous efforts by conducting a series of binding studies on ScaADoc constructs that contain mutations in their cohesin recognition interface, in order to identify which residues play important roles in binding. Molecular dynamics simulations were employed to gain insight into the structural basis for our findings. A specific residue pair in the first helix of ScaADoc, as well as a glutamate near the C-terminus, was identified to be essential for cohesin binding. By advancing our understanding of the cohesin binding of ScaADoc, this study serves as a foundation for future work to more fully understand the structural basis of cellulosome assembly in R. flavefaciens.
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Affiliation(s)
- Jonathan Y Weinstein
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel
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11
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Bule P, Ruimy-Israeli V, Cardoso V, Bayer EA, Fontes CMGA, Najmudin S. Overexpression, crystallization and preliminary X-ray characterization of Ruminococcus flavefaciens scaffoldin C cohesin in complex with a dockerin from an uncharacterized CBM-containing protein. Acta Crystallogr F Struct Biol Commun 2014; 70:1061-4. [PMID: 25084382 PMCID: PMC4118804 DOI: 10.1107/s2053230x14012667] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 05/30/2014] [Indexed: 11/10/2022] Open
Abstract
Cellulosomes are massive cell-bound multienzyme complexes tethered by macromolecular scaffolds that coordinate the efforts of many anaerobic bacteria to hydrolyze plant cell-wall polysaccharides, which are a major untapped source of carbon and energy. Integration of cellulosomal components occurs via highly ordered protein-protein interactions between cohesin modules, located in the scaffold, and dockerin modules, found in the enzymes and other cellulosomal proteins. The proposed cellulosomal architecture for Ruminococcus flavefaciens strain FD-1 consists of a major scaffoldin (ScaB) that acts as the backbone to which other components attach. It has nine cohesins and a dockerin with a fused X-module that binds to the cohesin on ScaE, which in turn is covalently attached to the cell wall. The ScaA dockerin binds to ScaB cohesins allowing more carbohydrate-active modules to be assembled. ScaC acts as an adaptor that binds to both ScaA and selected ScaB cohesins, thereby increasing the repertoire of dockerin-bearing proteins that integrate into the complex. In previous studies, a screen for novel cohesin-dockerin complexes was performed which led to the identification of a total of 58 probable cohesin-dockerin pairs. Four were selected for subsequent structural and biochemical characterization based on the quality of their expression and the diversity in their specificities. One of these is C12D22, which comprises the cohesin from the adaptor ScaC protein bound to the dockerin of a CBM-containing protein. This complex has been purified and crystallized, and data were collected to resolutions of 2.5 Å (hexagonal, P65), 2.16 Å (orthorhombic, P212121) and 2.4 Å (orthorhombic, P21212) from three different crystalline forms.
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Affiliation(s)
- Pedro Bule
- CIISA–Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Vered Ruimy-Israeli
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Vânia Cardoso
- CIISA–Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Edward A. Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Carlos M. G. A. Fontes
- CIISA–Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Shabir Najmudin
- CIISA–Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
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12
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Rumen cellulosomics: divergent fiber-degrading strategies revealed by comparative genome-wide analysis of six ruminococcal strains. PLoS One 2014; 9:e99221. [PMID: 24992679 PMCID: PMC4081043 DOI: 10.1371/journal.pone.0099221] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Accepted: 05/12/2014] [Indexed: 12/20/2022] Open
Abstract
Background A complex community of microorganisms is responsible for efficient plant cell wall digestion by many herbivores, notably the ruminants. Understanding the different fibrolytic mechanisms utilized by these bacteria has been of great interest in agricultural and technological fields, reinforced more recently by current efforts to convert cellulosic biomass to biofuels. Methodology/Principal Findings Here, we have used a bioinformatics-based approach to explore the cellulosome-related components of six genomes from two of the primary fiber-degrading bacteria in the rumen: Ruminococcus flavefaciens (strains FD-1, 007c and 17) and Ruminococcus albus (strains 7, 8 and SY3). The genomes of two of these strains are reported for the first time herein. The data reveal that the three R. flavefaciens strains encode for an elaborate reservoir of cohesin- and dockerin-containing proteins, whereas the three R. albus strains are cohesin-deficient and encode mainly dockerins and a unique family of cell-anchoring carbohydrate-binding modules (family 37). Conclusions/Significance Our comparative genome-wide analysis pinpoints rare and novel strain-specific protein architectures and provides an exhaustive profile of their numerous lignocellulose-degrading enzymes. This work provides blueprints of the divergent cellulolytic systems in these two prominent fibrolytic rumen bacterial species, each of which reflects a distinct mechanistic model for efficient degradation of cellulosic biomass.
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Ciric M, Moon CD, Leahy SC, Creevey CJ, Altermann E, Attwood GT, Rakonjac J, Gagic D. Metasecretome-selective phage display approach for mining the functional potential of a rumen microbial community. BMC Genomics 2014; 15:356. [PMID: 24886150 PMCID: PMC4035507 DOI: 10.1186/1471-2164-15-356] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 04/29/2014] [Indexed: 11/22/2022] Open
Abstract
Background In silico, secretome proteins can be predicted from completely sequenced genomes using various available algorithms that identify membrane-targeting sequences. For metasecretome (collection of surface, secreted and transmembrane proteins from environmental microbial communities) this approach is impractical, considering that the metasecretome open reading frames (ORFs) comprise only 10% to 30% of total metagenome, and are poorly represented in the dataset due to overall low coverage of metagenomic gene pool, even in large-scale projects. Results By combining secretome-selective phage display and next-generation sequencing, we focused the sequence analysis of complex rumen microbial community on the metasecretome component of the metagenome. This approach achieved high enrichment (29 fold) of secreted fibrolytic enzymes from the plant-adherent microbial community of the bovine rumen. In particular, we identified hundreds of heretofore rare modules belonging to cellulosomes, cell-surface complexes specialised for recognition and degradation of the plant fibre. Conclusions As a method, metasecretome phage display combined with next-generation sequencing has a power to sample the diversity of low-abundance surface and secreted proteins that would otherwise require exceptionally large metagenomic sequencing projects. As a resource, metasecretome display library backed by the dataset obtained by next-generation sequencing is ready for i) affinity selection by standard phage display methodology and ii) easy purification of displayed proteins as part of the virion for individual functional analysis. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-356) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | - Jasna Rakonjac
- Animal Nutrition and Health, AgResearch Ltd, Palmerston North 4442, New Zealand.
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14
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Vazana Y, Barak Y, Unger T, Peleg Y, Shamshoum M, Ben-Yehezkel T, Mazor Y, Shapiro E, Lamed R, Bayer EA. A synthetic biology approach for evaluating the functional contribution of designer cellulosome components to deconstruction of cellulosic substrates. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:182. [PMID: 24341331 PMCID: PMC3878649 DOI: 10.1186/1754-6834-6-182] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 11/27/2013] [Indexed: 05/04/2023]
Abstract
BACKGROUND Select cellulolytic bacteria produce multi-enzymatic cellulosome complexes that bind to the plant cell wall and catalyze its efficient degradation. The multi-modular interconnecting cellulosomal subunits comprise dockerin-containing enzymes that bind cohesively to cohesin-containing scaffoldins. The organization of the modules into functional polypeptides is achieved by intermodular linkers of different lengths and composition, which provide flexibility to the complex and determine its overall architecture. RESULTS Using a synthetic biology approach, we systematically investigated the spatial organization of the scaffoldin subunit and its effect on cellulose hydrolysis by designing a combinatorial library of recombinant trivalent designer scaffoldins, which contain a carbohydrate-binding module (CBM) and 3 divergent cohesin modules. The positions of the individual modules were shuffled into 24 different arrangements of chimaeric scaffoldins. This basic set was further extended into three sub-sets for each arrangement with intermodular linkers ranging from zero (no linkers), 5 (short linkers) and native linkers of 27-35 amino acids (long linkers). Of the 72 possible scaffoldins, 56 were successfully cloned and 45 of them expressed, representing 14 full sets of chimaeric scaffoldins. The resultant 42-component scaffoldin library was used to assemble designer cellulosomes, comprising three model C. thermocellum cellulases. Activities were examined using Avicel as a pure microcrystalline cellulose substrate and pretreated cellulose-enriched wheat straw as a model substrate derived from a native source. All scaffoldin combinations yielded active trivalent designer cellulosome assemblies on both substrates that exceeded the levels of the free enzyme systems. A preferred modular arrangement for the trivalent designer scaffoldin was not observed for the three enzymes used in this study, indicating that they could be integrated at any position in the designer cellulosome without significant effect on cellulose-degrading activity. Designer cellulosomes assembled with the long-linker scaffoldins achieved higher levels of activity, compared to those assembled with short-and no-linker scaffoldins. CONCLUSIONS The results demonstrate the robustness of the cellulosome system. Long intermodular scaffoldin linkers are preferable, thus leading to enhanced degradation of cellulosic substrates, presumably due to the increased flexibility and spatial positioning of the attached enzymes in the complex. These findings provide a general basis for improved designer cellulosome systems as a platform for bioethanol production.
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Affiliation(s)
- Yael Vazana
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yoav Barak
- Chemical Research Support, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Tamar Unger
- Structural Proteomics, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yoav Peleg
- Structural Proteomics, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Melina Shamshoum
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Tuval Ben-Yehezkel
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
- Department of Computer Science and Applied Mathematics, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yair Mazor
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
- Department of Computer Science and Applied Mathematics, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ehud Shapiro
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
- Department of Computer Science and Applied Mathematics, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Edward A Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
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15
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Chagnot C, Zorgani MA, Astruc T, Desvaux M. Proteinaceous determinants of surface colonization in bacteria: bacterial adhesion and biofilm formation from a protein secretion perspective. Front Microbiol 2013; 4:303. [PMID: 24133488 PMCID: PMC3796261 DOI: 10.3389/fmicb.2013.00303] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 09/22/2013] [Indexed: 01/30/2023] Open
Abstract
Bacterial colonization of biotic or abiotic surfaces results from two quite distinct physiological processes, namely bacterial adhesion and biofilm formation. Broadly speaking, a biofilm is defined as the sessile development of microbial cells. Biofilm formation arises following bacterial adhesion but not all single bacterial cells adhering reversibly or irreversibly engage inexorably into a sessile mode of growth. Among molecular determinants promoting bacterial colonization, surface proteins are the most functionally diverse active components. To be present on the bacterial cell surface, though, a protein must be secreted in the first place. Considering the close association of secreted proteins with their cognate secretion systems, the secretome (which refers both to the secretion systems and their protein substrates) is a key concept to apprehend the protein secretion and related physiological functions. The protein secretion systems are here considered in light of the differences in the cell-envelope architecture between diderm-LPS (archetypal Gram-negative), monoderm (archetypal Gram-positive) and diderm-mycolate (archetypal acid-fast) bacteria. Besides, their cognate secreted proteins engaged in the bacterial colonization process are regarded from single protein to supramolecular protein structure as well as the non-classical protein secretion. This state-of-the-art on the complement of the secretome (the secretion systems and their cognate effectors) involved in the surface colonization process in diderm-LPS and monoderm bacteria paves the way for future research directions in the field.
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Affiliation(s)
- Caroline Chagnot
- UR454 Microbiologie, INRA Saint-Genès Champanelle, France ; UR370 Qualité des Produits Animaux, INRA Saint-Genès Champanelle, France
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16
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Slutzki M, Jobby MK, Chitayat S, Karpol A, Dassa B, Barak Y, Lamed R, Smith SP, Bayer EA. Intramolecular clasp of the cellulosomal Ruminococcus flavefaciens ScaA dockerin module confers structural stability. FEBS Open Bio 2013; 3:398-405. [PMID: 24251102 PMCID: PMC3821032 DOI: 10.1016/j.fob.2013.09.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 09/20/2013] [Accepted: 09/20/2013] [Indexed: 12/02/2022] Open
Abstract
The cellulosome is a large extracellular multi-enzyme complex that facilitates the efficient hydrolysis and degradation of crystalline cellulosic substrates. During the course of our studies on the cellulosome of the rumen bacterium Ruminococcus flavefaciens, we focused on the critical ScaA dockerin (ScaADoc), the unique dockerin that incorporates the primary enzyme-integrating ScaA scaffoldin into the cohesin-bearing ScaB adaptor scaffoldin. In the absence of a high-resolution structure of the ScaADoc module, we generated a computational model, and, upon its analysis, we were surprised to discover a putative stacking interaction between an N-terminal Trp and a C-terminal Pro, which we termed intramolecular clasp. In order to verify the existence of such an interaction, these residues were mutated to alanine. Circular dichroism spectroscopy, intrinsic tryptophan and ANS fluorescence, and NMR spectroscopy indicated that mutation of these residues has a destabilizing effect on the functional integrity of the Ca2+-bound form of ScaADoc. Analysis of recently determined dockerin structures from other species revealed the presence of other well-defined intramolecular clasps, which consist of different types of interactions between selected residues at the dockerin termini. We propose that this thematic interaction may represent a major distinctive structural feature of the dockerin module. A structural model for the Ruminococcus flavefaciens ScaA dockerin is proposed. A stacking interaction between N- and C-terminal residues was derived from the model. Mutations of putative interacting residues resulted in reduced stability and binding. Similar intramodular “clasp” interactions were observed in other dockerin structures.
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Key Words
- ANS, 8-anilino-1-naphthalenesulfonate
- CBM, carbohydrate-binding module family 3a from C. thermocellum
- Cc, Clostridium cellulolyticum
- Coh, cohesin
- Cohesin
- Ct, Clostridium thermocellum
- Doc, dockerin
- HBS, hepes-buffered saline
- IPTG, isopropyl-1-thio-β-d-galactoside
- Protein stability
- Scaffoldin
- Stacking interaction
- TMB, 3,3′,5,5′-tetramethylbenzidine
- Xyn, xylanase T6 from Geobacillus stearothemophilus
- cELISA, competitive enzyme-linked interaction assay
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Affiliation(s)
- Michal Slutzki
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
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17
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Salama-Alber O, Jobby MK, Chitayat S, Smith SP, White BA, Shimon LJW, Lamed R, Frolow F, Bayer EA. Atypical cohesin-dockerin complex responsible for cell surface attachment of cellulosomal components: binding fidelity, promiscuity, and structural buttresses. J Biol Chem 2013; 288:16827-16838. [PMID: 23580648 PMCID: PMC3675615 DOI: 10.1074/jbc.m113.466672] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 04/07/2013] [Indexed: 01/01/2023] Open
Abstract
The rumen bacterium Ruminococcus flavefaciens produces a highly organized multienzyme cellulosome complex that plays a key role in the degradation of plant cell wall polysaccharides, notably cellulose. The R. flavefaciens cellulosomal system is anchored to the bacterial cell wall through a relatively small ScaE scaffoldin subunit, which bears a single type IIIe cohesin responsible for the attachment of two major dockerin-containing scaffoldin proteins, ScaB and the cellulose-binding protein CttA. Although ScaB recruits the catalytic machinery onto the complex, CttA mediates attachment of the bacterial substrate via its two putative carbohydrate-binding modules. In an effort to understand the structural basis for assembly and cell surface attachment of the cellulosome in R. flavefaciens, we determined the crystal structure of the high affinity complex (Kd = 20.83 nM) between the cohesin module of ScaE (CohE) and its cognate X-dockerin (XDoc) modular dyad from CttA at 1.97-Å resolution. The structure reveals an atypical calcium-binding loop containing a 13-residue insert. The results further pinpoint two charged specificity-related residues on the surface of the cohesin module that are responsible for specific versus promiscuous cross-strain binding of the dockerin module. In addition, a combined functional role for the three enigmatic dockerin inserts was established whereby these extraneous segments serve as structural buttresses that reinforce the stalklike conformation of the X-module, thus segregating its tethered complement of cellulosomal components from the cell surface. The novel structure of the RfCohE-XDoc complex sheds light on divergent dockerin structure and function and provides insight into the specificity features of the type IIIe cohesin-dockerin interaction.
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Affiliation(s)
| | - Maroor K Jobby
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Seth Chitayat
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Steven P Smith
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Bryan A White
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Linda J W Shimon
- Chemical Services, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Ramat Aviv 69978, Israel
| | - Felix Frolow
- Department of Molecular Microbiology and Biotechnology, Ramat Aviv 69978, Israel; Daniella Rich Institute for Structural Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv 69978, Israel.
| | - Edward A Bayer
- Departments of Biological Chemistry, Rehovot 76100, Israel.
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Vodovnik M, Duncan SH, Reid MD, Cantlay L, Turner K, Parkhill J, Lamed R, Yeoman CJ, Miller MEB, White BA, Bayer EA, Marinšek-Logar R, Flint HJ. Expression of cellulosome components and type IV pili within the extracellular proteome of Ruminococcus flavefaciens 007. PLoS One 2013; 8:e65333. [PMID: 23750253 PMCID: PMC3672088 DOI: 10.1371/journal.pone.0065333] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Accepted: 04/24/2013] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Ruminococcus flavefaciens is an important fibre-degrading bacterium found in the mammalian gut. Cellulolytic strains from the bovine rumen have been shown to produce complex cellulosome structures that are associated with the cell surface. R. flavefaciens 007 is a highly cellulolytic strain whose ability to degrade dewaxed cotton, but not Avicel cellulose, was lost following initial isolation in the variant 007S. The ability was recovered after serial subculture to give the cotton-degrading strain 007C. This has allowed us to investigate the factors required for degradation of this particularly recalcitrant form of cellulose. METHODOLOGY/PRINCIPAL FINDINGS The major proteins associated with the bacterial cell surface and with the culture supernatant were analyzed for R. flavefaciens 007S and 007C grown with cellobiose, xylan or Avicel cellulose as energy sources. Identification of the proteins was enabled by a draft genome sequence obtained for 007C. Among supernatant proteins a cellulosomal GH48 hydrolase, a rubrerthyrin-like protein and a protein with type IV pili N-terminal domain were the most strongly up-regulated in 007C cultures grown on Avicel compared with cellobiose. Strain 007S also showed substrate-related changes, but supernatant expression of the Pil protein and rubrerythrin in particular were markedly lower in 007S than in 007C during growth on Avicel. CONCLUSIONS/SIGNIFICANCE This study provides new information on the extracellular proteome of R. flavefaciens and its regulation in response to different growth substrates. Furthermore it suggests that the cotton cellulose non-degrading strain (007S) has altered regulation of multiple proteins that may be required for breakdown of cotton cellulose. One of these, the type IV pilus was previously shown to play a role in adhesion to cellulose in R. albus, and a related pilin protein was identified here for the first time as a major extracellular protein in R. flavefaciens.
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Affiliation(s)
- Maša Vodovnik
- Chair for Microbiology and Microbial Biotechnology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Sylvia H. Duncan
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Martin D. Reid
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Louise Cantlay
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Keith Turner
- Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | | | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Carl J. Yeoman
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Margret E. Berg. Miller
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Bryan A. White
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Edward A. Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Romana Marinšek-Logar
- Chair for Microbiology and Microbial Biotechnology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Harry J. Flint
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
- * E-mail: .
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19
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Crystal structure of an uncommon cellulosome-related protein module from Ruminococcus flavefaciens that resembles papain-like cysteine peptidases. PLoS One 2013; 8:e56138. [PMID: 23457513 PMCID: PMC3573020 DOI: 10.1371/journal.pone.0056138] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2012] [Accepted: 01/05/2013] [Indexed: 11/19/2022] Open
Abstract
Background Ruminococcus flavefaciens is one of the predominant fiber-degrading bacteria found in the rumen of herbivores. Bioinformatic analysis of the recently sequenced genome indicated that this bacterium produces one of the most intricate cellulosome systems known to date. A distinct ORF, encoding for a multi-modular protein, RflaF_05439, was discovered during mining of the genome sequence. It is composed of two tandem modules of currently undefined function that share 45% identity and a C-terminal X-dockerin modular dyad. Gaining insight into the diversity, architecture and organization of different types of proteins in the cellulosome system is essential for broadening our understanding of a multi-enzyme complex, considered to be one of the most efficient systems for plant cell wall polysaccharide degradation in nature. Methodology/Principal Findings Following bioinformatic analysis, the second tandem module of RflaF_05439 was cloned and its selenium-labeled derivative was expressed and crystallized. The crystals belong to space group P21 with unit-cell parameters of a = 65.81, b = 60.61, c = 66.13 Å, β = 107.66° and contain two protein molecules in the asymmetric unit. The crystal structure was determined at 1.38-Å resolution by X-ray diffraction using the single-wavelength anomalous dispersion (SAD) method and was refined to Rfactor and Rfree of 0.127 and 0.152 respectively. The protein molecule mainly comprises a β-sheet flanked by short α-helixes, and a globular α-helical domain. The structure was found to be structurally similar to members of the NlpC/P60 superfamily of cysteine peptidases. Conclusions/Significance The 3D structure of the second repeat of the RflaF_05439 enabled us to propose a role for the currently undefined function of this protein. Its putative function as a cysteine peptidase is inferred from in silico structural homology studies. It is therefore apparent that cellulosomes integrate proteins with other functions in addition to the classic well-defined carbohydrate active enzymes.
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Karpol A, Jobby MK, Slutzki M, Noach I, Chitayat S, Smith SP, Bayer EA. Structural and functional characterization of a novel type-III dockerin from Ruminococcus flavefaciens. FEBS Lett 2013; 587:30-6. [PMID: 23195689 DOI: 10.1016/j.febslet.2012.11.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 10/19/2012] [Accepted: 11/06/2012] [Indexed: 11/17/2022]
Abstract
Phylogenetic analysis of known dockerins in Ruminococcus flavefaciens revealed a novel subtype, type-III, in the scaffoldin proteins, ScaA, ScaB, ScaC and ScaE. In this study, we explored the Ca²⁺-binding properties of the type-III dockerin from the ScaA scaffoldin (ScaADoc) using a battery of structural and biophysical approaches including circular dichroism spectroscopy, isothermal titration calorimetry, differential scanning calorimetry, and nuclear magnetic resonance spectroscopy. Despite the lack of a second canonical Ca²⁺-binding loop, the behaviour of ScaADoc is similar with respect to other dockerin protein modules in terms of its responsiveness to Ca²⁺ and affinity for the cohesin from the ScaB scaffoldin. Our results highlight the robustness of dockerin modules and how their Ca²⁺-binding properties can be exploited in the construction of designer cellulosomes.
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Affiliation(s)
- Alon Karpol
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
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Wieczorek AS, Martin VJJ. Effects of synthetic cohesin-containing scaffold protein architecture on binding dockerin-enzyme fusions on the surface of Lactococcus lactis. Microb Cell Fact 2012; 11:160. [PMID: 23241215 PMCID: PMC3542058 DOI: 10.1186/1475-2859-11-160] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 12/05/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The microbial synthesis of fuels, commodity chemicals, and bioactive compounds necessitates the assemblage of multiple enzyme activities to carry out sequential chemical reactions, often via substrate channeling by means of multi-domain or multi-enzyme complexes. Engineering the controlled incorporation of enzymes in recombinant protein complexes is therefore of interest. The cellulosome of Clostridium thermocellum is an extracellular enzyme complex that efficiently hydrolyzes crystalline cellulose. Enzymes interact with protein scaffolds via type 1 dockerin/cohesin interactions, while scaffolds in turn bind surface anchor proteins by means of type 2 dockerin/cohesin interactions, which demonstrate a different binding specificity than their type 1 counterparts. Recombinant chimeric scaffold proteins containing cohesins of different specificity allow binding of multiple enzymes to specific sites within an engineered complex. RESULTS We report the successful display of engineered chimeric scaffold proteins containing both type 1 and type 2 cohesins on the surface of Lactococcus lactis cells. The chimeric scaffold proteins were able to form complexes with the Escherichia coli β-glucuronidase fused to either type 1 or type 2 dockerin, and differences in binding efficiencies were correlated with scaffold architecture. We used E. coli β-galactosidase, also fused to type 1 or type 2 dockerins, to demonstrate the targeted incorporation of two enzymes into the complexes. The simultaneous binding of enzyme pairs each containing a different dockerin resulted in bi-enzymatic complexes tethered to the cell surface. The sequential binding of the two enzymes yielded insights into parameters affecting assembly of the complex such as protein size and position within the scaffold. CONCLUSIONS The spatial organization of enzymes into complexes is an important strategy for increasing the efficiency of biochemical pathways. In this study, chimeric protein scaffolds consisting of type 1 and type 2 cohesins anchored on the surface of L. lactis allowed for the controlled positioning of dockerin-fused reporter enzymes onto the scaffolds. By binding single enzymes or enzyme pairs to the scaffolds, our data also suggest that the size and relative positions of enzymes can affect the catalytic profiles of the resulting complexes. These insights will be of great value as we engineer more advanced scaffold-guided protein complexes to optimize biochemical pathways.
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Affiliation(s)
- Andrew S Wieczorek
- Department of Biology, Centre for Structural and Functional Genomics, Concordia University, Montréal, Québec, H4B 1R6, Canada
| | - Vincent JJ Martin
- Department of Biology, Centre for Structural and Functional Genomics, Concordia University, Montréal, Québec, H4B 1R6, Canada
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Abstract
Analysis of 16S ribosomal RNA (rRNA)-encoding gene sequences from gut microbial ecosystems reveals bewildering genetic diversity. Some metabolic functions, such as glucose utilisation, are fairly widespread throughout the genetic spectrum. Others, however, are not. Despite so many phylotypes being present, single species or perhaps only two or three species often carry out key functions. Among ruminal bacteria, only three species can break down highly structured cellulose, despite the prevalence and importance of cellulose in ruminant diets, and one of those species, Fibrobacter succinogenes, is distantly related to the most abundant ruminal species. Fatty acid biohydrogenation in the rumen, particularly the final step of biohydrogenation of C18 fatty acids, stearate formation, is achieved only by a small sub-group of bacteria related to Butyrivibrio fibrisolvens. Individuals who lack Oxalobacter formigenes fail to metabolise oxalate and suffer kidney stones composed of calcium oxalate. Perhaps the most celebrated example of the difference a single species can make is the 'mimosine story' in ruminants. Mimosine is a toxic amino acid found in the leguminous plant, Leucaena leucocephala. Mimosine can cause thyroid problems by being converted to the goitrogen, 3-hydroxy-4(1H)-pyridone, in the rumen. Observations that mimosine-containing plants were toxic to ruminants in some countries but not others led to the discovery of Synergistes jonesii, which metabolises 3-hydroxy-4(1H)-pyridone and protects animals from toxicity. Thus, despite the complexities indicated by molecular microbial ecology and genomics, it should never be forgotten that gut communities contain important metabolic niches inhabited by species with highly specific metabolic capability.
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Vodovnik M, Logar RM. Expression patterns of Ruminococcus flavefaciens 007S cellulases as revealed by zymogram approach. Folia Microbiol (Praha) 2012; 57:367-70. [DOI: 10.1007/s12223-012-0144-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 01/04/2012] [Indexed: 11/28/2022]
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Warner CD, Camci-Unal G, Pohl NLB, Ford C, Reilly PJ. Substrate Binding by the Catalytic Domain and Carbohydrate Binding Module ofRuminococcus flavefaciensFD-1 Xyloglucanase/Endoglucanase. Ind Eng Chem Res 2012. [DOI: 10.1021/ie202988a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Jeon SD, Yu KO, Kim SW, Han SO. The processive endoglucanase EngZ is active in crystalline cellulose degradation as a cellulosomal subunit of Clostridium cellulovorans. N Biotechnol 2012; 29:365-71. [DOI: 10.1016/j.nbt.2011.06.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 05/17/2011] [Accepted: 06/01/2011] [Indexed: 10/18/2022]
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Jeon SD, Yu KO, Kim SW, Han SO. A celluloytic complex from Clostridium cellulovorans consisting of mannanase B and endoglucanase E has synergistic effects on galactomannan degradation. Appl Microbiol Biotechnol 2011; 90:565-72. [DOI: 10.1007/s00253-011-3108-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 12/30/2010] [Accepted: 01/05/2011] [Indexed: 10/18/2022]
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Warner CD, Go RM, García-Salinas C, Ford C, Reilly PJ. Kinetic characterization of a glycoside hydrolase family 44 xyloglucanase/endoglucanase from Ruminococcus flavefaciens FD-1. Enzyme Microb Technol 2011; 48:27-32. [DOI: 10.1016/j.enzmictec.2010.08.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 08/26/2010] [Accepted: 08/31/2010] [Indexed: 11/16/2022]
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Rincon MT, Dassa B, Flint HJ, Travis AJ, Jindou S, Borovok I, Lamed R, Bayer EA, Henrissat B, Coutinho PM, Antonopoulos DA, Berg Miller ME, White BA. Abundance and diversity of dockerin-containing proteins in the fiber-degrading rumen bacterium, Ruminococcus flavefaciens FD-1. PLoS One 2010; 5:e12476. [PMID: 20814577 PMCID: PMC2930009 DOI: 10.1371/journal.pone.0012476] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Accepted: 08/03/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The cellulosome is a multi-enzyme machine, which plays a key role in the breakdown of plant cell walls in many anaerobic cellulose-degrading microorganisms. Ruminococcus flavefaciens FD-1, a major fiber-degrading bacterium present in the gut of herbivores, has the most intricate cellulosomal organization thus far described. Cellulosome complexes are assembled through high-affinity cohesin-dockerin interactions. More than two-hundred dockerin-containing proteins have been identified in the R. flavefaciens genome, yet the reason for the expansion of these crucial cellulosomal components is yet unknown. METHODOLOGY/PRINCIPAL FINDINGS We have explored the full spectrum of 222 dockerin-containing proteins potentially involved in the assembly of cellulosome-like complexes of R. flavefaciens. Bioinformatic analysis of the various dockerin modules showed distinctive conservation patterns within their two Ca(2+)-binding repeats and their flanking regions. Thus, we established the conceptual framework for six major groups of dockerin types, according to their unique sequence features. Within this framework, the modular architecture of the parent proteins, some of which are multi-functional proteins, was evaluated together with their gene expression levels. Specific dockerin types were found to be associated with selected groups of functional components, such as carbohydrate-binding modules, numerous peptidases, and/or carbohydrate-active enzymes. In addition, members of other dockerin groups were linked to structural proteins, e.g., cohesin-containing proteins, belonging to the scaffoldins. CONCLUSIONS/SIGNIFICANCE This report profiles the abundance and sequence diversity of the R. flavefaciens FD-1 dockerins, and provides the molecular basis for future understanding of the potential for a wide array of cohesin-dockerin specificities. Conserved differences between dockerins may be reflected in their stability, function or expression within the context of the parent protein, in response to their role in the rumen environment.
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Affiliation(s)
- Marco T. Rincon
- Microbial Ecology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Bareket Dassa
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Harry J. Flint
- Microbial Ecology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Anthony J. Travis
- Microbial Ecology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Sadanari Jindou
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Edward A. Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Bernard Henrissat
- Architecture et Fonction des Macromolecules Biologiques, CNRS and Universites d'Aix-Marseille I & II, Marseille, France
| | - Pedro M. Coutinho
- Architecture et Fonction des Macromolecules Biologiques, CNRS and Universites d'Aix-Marseille I & II, Marseille, France
| | - Dion A. Antonopoulos
- Division of Nutritional Sciences, Department of Animal Sciences, North American Consortium for Genomics of Fibrolytic Ruminal Bacteria, University of Illinois, Urbana, Illinois, United States of America
| | - Margret E. Berg Miller
- Division of Nutritional Sciences, Department of Animal Sciences, North American Consortium for Genomics of Fibrolytic Ruminal Bacteria, University of Illinois, Urbana, Illinois, United States of America
| | - Bryan A. White
- Division of Nutritional Sciences, Department of Animal Sciences, North American Consortium for Genomics of Fibrolytic Ruminal Bacteria, University of Illinois, Urbana, Illinois, United States of America
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van Dyk JS, Sakka M, Sakka K, Pletschke BI. Identification of endoglucanases, xylanases, pectinases and mannanases in the multi-enzyme complex of Bacillus licheniformis SVD1. Enzyme Microb Technol 2010. [DOI: 10.1016/j.enzmictec.2010.05.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Fontes CMGA, Gilbert HJ. Cellulosomes: highly efficient nanomachines designed to deconstruct plant cell wall complex carbohydrates. Annu Rev Biochem 2010; 79:655-81. [PMID: 20373916 DOI: 10.1146/annurev-biochem-091208-085603] [Citation(s) in RCA: 361] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cellulosomes can be described as one of nature's most elaborate and highly efficient nanomachines. These cell bound multienzyme complexes orchestrate the deconstruction of cellulose and hemicellulose, two of the most abundant polymers on Earth, and thus play a major role in carbon turnover. Integration of cellulosomal components occurs via highly ordered protein:protein interactions between cohesins and dockerins, whose specificity allows the incorporation of cellulases and hemicellulases onto a molecular scaffold. Cellulosome assembly promotes the exploitation of enzyme synergism because of spatial proximity and enzyme-substrate targeting. Recent structural and functional studies have revealed how cohesin-dockerin interactions mediate both cellulosome assembly and cell-surface attachment, while retaining the spatial flexibility required to optimize the catalytic synergy within the enzyme complex. These emerging advances in our knowledge of cellulosome function are reviewed here.
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Affiliation(s)
- Carlos M G A Fontes
- CIISA, Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, 1300-477 Lisboa, Portugal.
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Alber O, Noach I, Rincon MT, Flint HJ, Shimon LJW, Lamed R, Frolow F, Bayer EA. Cohesin diversity revealed by the crystal structure of the anchoring cohesin from Ruminococcus flavefaciens. Proteins 2009; 77:699-709. [PMID: 19544570 DOI: 10.1002/prot.22483] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The cellulosome is an intriguing multienzyme complex found in cellulolytic bacteria that plays a key role in the degradation of plant cell-wall polysaccharides. In Ruminococcus flavefaciens, a predominant fiber-degrading bacterium found in ruminants, the cellulosome is anchored to the bacterial cell wall through a relatively short ScaE scaffoldin. Determination of the crystal structure of the lone type-III ScaE cohesin from R. flavefaciens (Rf-CohE) was initiated as a part of a structural effort to define cellulosome assembly. The structure was determined at 1.95 A resolution by single-wavelength anomalous diffraction. This is the first detailed description of a crystal structure for a type-III cohesin, and its features were compared with those of the known type-I and type-II cohesin structures. The Rf-CohE module folds into a nine-stranded beta-sandwich with jellyroll topology, typically observed for cohesins, and includes two beta-flaps in the midst of beta-strands 4 and 8, similar to the type-II cohesin structures. However, the presence in Rf-CohE of an additional 13-residue alpha-helix located between beta-strands 8 and 9 represents a dramatic divergence from other known cohesin structures. The prominent alpha-helix is enveloped by an extensive N-terminal loop, not observed in any other known cohesin, which embraces the helix presumably enhancing its stability. A planar surface at the upper portion of the front face of the molecule, bordered by beta-flap 8, exhibits plausible dimensions and exposed amino acid residues to accommodate the dockerin-binding site.
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Affiliation(s)
- Orly Alber
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
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Berg Miller ME, Antonopoulos DA, Rincon MT, Band M, Bari A, Akraiko T, Hernandez A, Thimmapuram J, Henrissat B, Coutinho PM, Borovok I, Jindou S, Lamed R, Flint HJ, Bayer EA, White BA. Diversity and strain specificity of plant cell wall degrading enzymes revealed by the draft genome of Ruminococcus flavefaciens FD-1. PLoS One 2009; 4:e6650. [PMID: 19680555 PMCID: PMC2721979 DOI: 10.1371/journal.pone.0006650] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Accepted: 07/07/2009] [Indexed: 11/19/2022] Open
Abstract
Background Ruminococcus flavefaciens is a predominant cellulolytic rumen bacterium, which forms a multi-enzyme cellulosome complex that could play an integral role in the ability of this bacterium to degrade plant cell wall polysaccharides. Identifying the major enzyme types involved in plant cell wall degradation is essential for gaining a better understanding of the cellulolytic capabilities of this organism as well as highlighting potential enzymes for application in improvement of livestock nutrition and for conversion of cellulosic biomass to liquid fuels. Methodology/Principal Findings The R. flavefaciens FD-1 genome was sequenced to 29x-coverage, based on pulsed-field gel electrophoresis estimates (4.4 Mb), and assembled into 119 contigs providing 4,576,399 bp of unique sequence. As much as 87.1% of the genome encodes ORFs, tRNA, rRNAs, or repeats. The GC content was calculated at 45%. A total of 4,339 ORFs was detected with an average gene length of 918 bp. The cellulosome model for R. flavefaciens was further refined by sequence analysis, with at least 225 dockerin-containing ORFs, including previously characterized cohesin-containing scaffoldin molecules. These dockerin-containing ORFs encode a variety of catalytic modules including glycoside hydrolases (GHs), polysaccharide lyases, and carbohydrate esterases. Additionally, 56 ORFs encode proteins that contain carbohydrate-binding modules (CBMs). Functional microarray analysis of the genome revealed that 56 of the cellulosome-associated ORFs were up-regulated, 14 were down-regulated, 135 were unaffected, when R. flavefaciens FD-1 was grown on cellulose versus cellobiose. Three multi-modular xylanases (ORF01222, ORF03896, and ORF01315) exhibited the highest levels of up-regulation. Conclusions/Significance The genomic evidence indicates that R. flavefaciens FD-1 has the largest known number of fiber-degrading enzymes likely to be arranged in a cellulosome architecture. Functional analysis of the genome has revealed that the growth substrate drives expression of enzymes predicted to be involved in carbohydrate metabolism as well as expression and assembly of key cellulosomal enzyme components.
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Affiliation(s)
- Margret E. Berg Miller
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Dionysios A. Antonopoulos
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Marco T. Rincon
- Microbial Ecology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Mark Band
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Albert Bari
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Tatsiana Akraiko
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Alvaro Hernandez
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Jyothi Thimmapuram
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, CNRS and Universités Aix-Marseille I & II, Marseille, France
| | - Pedro M. Coutinho
- Architecture et Fonction des Macromolécules Biologiques, CNRS and Universités Aix-Marseille I & II, Marseille, France
| | - Ilya Borovok
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Sadanari Jindou
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Harry J. Flint
- Microbial Ecology Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Edward A. Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
| | - Bryan A. White
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- * E-mail:
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Plant biomass degradation by gut microbiomes: more of the same or something new? Curr Opin Biotechnol 2009; 20:358-63. [PMID: 19515552 DOI: 10.1016/j.copbio.2009.05.004] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2009] [Revised: 05/13/2009] [Accepted: 05/14/2009] [Indexed: 11/21/2022]
Abstract
Herbivores retain within their gastrointestinal tract a microbiome that specializes in the rapid hydrolysis and fermentation of lignocellulosic plant biomass. With the emergence of high-throughput DNA sequencing technologies and related 'omics' approaches, along with demands to better utilize lignocellulose materials as a feedstock for second-generation biofuels, these gut microbiomes are thought to be a potential source of novel biotechnologies relevant to meeting these needs. This review provides an insight into the new findings that have arisen from the (meta)genomic analysis of specialist cellulolytic bacteria and gut microbiomes of herbivorous insects, ruminants, native Australian marsupials, and other obligate herbivores. In addition to there being more of the same in terms of cellulases and cellulosomes, there also appears to be something 'new' in terms of the compositional and functional attributes of the plant cell wall deconstruction systems employed by these bacteria. However, future dissection and capture of useful biotechnologies via metagenomics will need more than the production of data using next generation sequencing technologies.
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Fendri I, Tardif C, Fierobe HP, Lignon S, Valette O, Pagès S, Perret S. The cellulosomes fromClostridium cellulolyticum. FEBS J 2009; 276:3076-86. [DOI: 10.1111/j.1742-4658.2009.07025.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Cellulosomes are intricate multienzyme systems produced by several cellulolytic bacteria, the first example of which was discovered in the anaerobic thermophilic bacterium, Clostridium thermocellum. Cellulosomes are designed for efficient degradation of plant cell wall polysaccharides, notably cellulose--the most abundant renewable polymer on earth. The component parts of the multicomponent complex are integrated by virtue of a unique family of integrating modules, the cohesins and the dockerins, whose distribution and specificity dictate the overall cellulosome architecture. A full generation of research has elapsed since the original publications that documented the cellulosome concept. In this review, we provide a personal account on the discovery process, while describing how divergent cellulosome systems were identified and investigated, culminating in the collaboration of several labs worldwide to tackle together the challenging field of cellulosome genomics and metagenomics.
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Affiliation(s)
- Edward A Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel.
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Peer A, Smith SP, Bayer EA, Lamed R, Borovok I. Noncellulosomal cohesin- and dockerin-like modules in the three domains of life. FEMS Microbiol Lett 2008; 291:1-16. [PMID: 19025568 DOI: 10.1111/j.1574-6968.2008.01420.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The high-affinity cohesin-dockerin interaction was originally discovered as modular components, which mediate the assembly of the various subunits of the multienzyme cellulosome complex that characterizes some cellulolytic bacteria. Until recently, the presence of cohesins and dockerins within a bacterial proteome was considered a definitive signature of a cellulosome-producing bacterium. Widespread genome sequencing has since revealed a wealth of putative cohesin- and dockerin-containing proteins in Bacteria, Archaea, and in primitive eukaryotes. The newly identified modules appear to serve diverse functions that are clearly distinct from the classical cellulosome archetype, and the vast majority of parent proteins are not predicted glycoside hydrolases. In most cases, only a few such genes have been identified in a given microorganism, which encode proteins containing but a single cohesin and/or dockerin. In some cases, one or the other module appears to be missing from a given species, and in other cases both modules occur within the same protein. This review provides a bioinformatics-based survey of the current status of cohesin- and dockerin-like sequences in species from the Bacteria, Archaea, and Eukarya. Surprisingly, many identified modules and their parent proteins are clearly unrelated to cellulosomes. The cellulosome paradigm may thus be the exception rather than the rule for bacterial, archaeal, and eukaryotic employment of cohesin and dockerin modules.
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Affiliation(s)
- Ayelet Peer
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
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Flint HJ, Bayer EA. Plant cell wall breakdown by anaerobic microorganisms from the Mammalian digestive tract. Ann N Y Acad Sci 2008; 1125:280-8. [PMID: 18378598 DOI: 10.1196/annals.1419.022] [Citation(s) in RCA: 151] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Degradation of lignocellulosic plant material in the mammalian digestive tract is accomplished by communities of anaerobic microorganisms that exist in symbiotic association with the host. Catalytic domains and substrate-binding modules concerned with plant polysaccharide degradation are found in a variety of anaerobic bacteria, fungi, and protozoa from the mammalian gut. The organization of plant cell wall-degrading enzymes, however, varies widely. The cellulolytic gram-positive bacterium Ruminococcus flavefaciens produces an elaborate cellulosomal enzyme complex that is anchored to the bacterial cell wall; assembly of the complex involves at least five different dockerin:cohesin specificities, and the R. flavefaciens genome encodes at least 180 dockerin-containing proteins that encompass a wide array of catalytic and binding activities. On the other hand, in the cellulolytic protozoan, Polyplastron multivesiculatum, individual plant cell wall-degrading enzymes appear to be secreted into food vacuoles, while the gram-negative bacterium Prevotella bryantii appears to possess a sequestration-type system for the utilization of soluble xylans. The system that is employed for polysaccharide utilization must play a major role in defining the ecological niche that each organism occupies within a complex gut community. 16S rRNA analyses are also revealing uncultured bacterial species closely adherent to fibrous substrates in the rumen and in the large intestine of animals and humans. The true complexity, both at a single organism and community level, of the microbial enzyme systems that allow animals to digest plant material is beginning to become apparent.
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Affiliation(s)
- Harry J Flint
- Microbial Ecology Group, Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, UK.
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39
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Haimovitz R, Barak Y, Morag E, Voronov-Goldman M, Shoham Y, Lamed R, Bayer EA. Cohesin-dockerin microarray: Diverse specificities between two complementary families of interacting protein modules. Proteomics 2008; 8:968-79. [PMID: 18219699 DOI: 10.1002/pmic.200700486] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Indexed: 11/10/2022]
Abstract
The cellulosome is an intricate multienzyme complex, designed for efficient degradation of plant cell wall polysaccharides, notably cellulose. The supramolecular cellulosome architecture in different bacteria is the consequence of the types and specificities of the interacting cohesin and dockerin modules, borne by the different cellulosomal subunits. In this study, we describe a microarray system for determining cohesin-dockerin specificity, which allows global comparison among the interactions between various members of these two complementary families of interacting protein modules. Matching recombinant fusion proteins were prepared that contained one of the interacting modules: cohesins were joined to an appropriate cellulose-binding module (CBM) and the dockerins were fused to a thermostable xylanase that served to enhance expression and proper folding. The CBM-fused cohesins were immobilized on cellulose-coated glass slides, to which xylanase-fused dockerin samples were applied. Knowledge of the specificity characteristics of native and mutated members of the cohesin and dockerin families provides insight into the architecture of the parent cellulosome and allows selection of suitable cohesin-dockein pairs for biotechnological and nanotechnological application. Using this approach, extensive cross-species interaction among type-II cohesins and dockerins is shown for the first time. Selective intraspecies binding of an archaeal dockerin to two complementary cohesins is also demonstrated.
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Affiliation(s)
- Rachel Haimovitz
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
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40
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Karpol A, Barak Y, Lamed R, Shoham Y, Bayer EA. Functional asymmetry in cohesin binding belies inherent symmetry of the dockerin module: insight into cellulosome assembly revealed by systematic mutagenesis. Biochem J 2008; 410:331-8. [PMID: 18021074 DOI: 10.1042/bj20071193] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
The cellulosome is an intricate multi-enzyme complex, known for its efficient degradation of recalcitrant cellulosic substrates. Its supramolecular architecture is determined by the high-affinity intermodular cohesin-dockerin interaction. The dockerin module comprises a calcium-binding, duplicated 'F-hand' loop-helix motif that bears striking similarity to the EF-hand loop-helix-loop motif of eukaryotic calcium-binding proteins. In the present study, we demonstrate by progressive truncation and alanine scanning of a representative type-I dockerin module from Clostridium thermocellum, that only one of the repeated motifs is critical for high-affinity cohesin binding. The results suggest that the near-symmetry in sequence and structure of the repeated elements of the dockerin is not essential to cohesin binding. The first calcium-binding loop can be deleted entirely, with almost full retention of binding. Likewise, significant deletion of the second repeated segment can be achieved, provided that its calcium-binding loop remains intact. Essentially the same conclusion was verified by systematically mutating the highly conserved residues in the calcium-binding loop. Mutations in one of the calcium-binding loops failed to disrupt cohesin recognition and binding, whereas a single mutation in both loops served to reduce the affinity significantly. The results are mutually compatible with recent crystal structures of the type-I cohesin-dockerin heterodimer, which demonstrate that the dockerin can bind in an equivalent manner to its cohesin counterpart through either its first or second repeated motif. The observed plasticity in cohesin-dockerin binding may facilitate cellulosome assembly in vivo or, alternatively, provide a conformational switch that promotes access of the tethered cellulosomal enzymes to their polysaccharide substrates.
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Affiliation(s)
- Alon Karpol
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, 76100 Israel
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41
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Polysaccharide utilization by gut bacteria: potential for new insights from genomic analysis. Nat Rev Microbiol 2008; 6:121-31. [PMID: 18180751 DOI: 10.1038/nrmicro1817] [Citation(s) in RCA: 1080] [Impact Index Per Article: 67.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The microbiota of the mammalian intestine depend largely on dietary polysaccharides as energy sources. Most of these polymers are not degradable by the host, but herbivores can derive 70% of their energy intake from microbial breakdown--a classic example of mutualism. Moreover, dietary polysaccharides that reach the human large intestine have a major impact on gut microbial ecology and health. Insight into the molecular mechanisms by which different gut bacteria use polysaccharides is, therefore, of fundamental importance. Genomic analyses of the gut microbiota could revolutionize our understanding of these mechanisms and provide new biotechnological tools for the conversion of polysaccharides, including lignocellulosic biomass, into monosaccharides.
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42
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Alber O, Noach I, Lamed R, Shimon LJW, Bayer EA, Frolow F. Preliminary X-ray characterization of a novel type of anchoring cohesin from the cellulosome of Ruminococcus flavefaciens. Acta Crystallogr Sect F Struct Biol Cryst Commun 2008; 64:77-80. [PMID: 18259053 PMCID: PMC2374186 DOI: 10.1107/s1744309107067437] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2007] [Accepted: 12/17/2007] [Indexed: 11/10/2022]
Abstract
Ruminococcus flavefaciens is an anaerobic bacterium that resides in the gastrointestinal tract of ruminants. It produces a highly organized multi-enzyme cellulosome complex that plays a key role in the degradation of plant cell walls. ScaE is one of the critical structural components of its cellulosome that serves to anchor the complex to the cell wall. The seleno-L-methionine-labelled derivative of the ScaE cohesin module has been cloned, expressed, purified and crystallized. The crystals belong to space group C2, with unit-cell parameters a = 155.6, b = 69.3, c = 93.0 A, beta = 123.4 degrees, and contain four molecules in the asymmetric unit. Diffraction data were phased to 1.95 A using the anomalous signal from the Se atoms.
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Affiliation(s)
- Orly Alber
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ilit Noach
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
- The Daniella Rich Institute for Structural Biology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Linda J. W. Shimon
- Department of Chemical Research Support, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Edward A. Bayer
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Felix Frolow
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel
- The Daniella Rich Institute for Structural Biology, Tel Aviv University, Tel Aviv 69978, Israel
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43
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Rincon MT, Cepeljnik T, Martin JC, Barak Y, Lamed R, Bayer EA, Flint HJ. A novel cell surface-anchored cellulose-binding protein encoded by the sca gene cluster of Ruminococcus flavefaciens. J Bacteriol 2007; 189:4774-83. [PMID: 17468247 PMCID: PMC1913464 DOI: 10.1128/jb.00143-07] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ruminococcus flavefaciens produces a cellulosomal enzyme complex, based on the structural proteins ScaA, -B, and -C, that was recently shown to attach to the bacterial cell surface via the wall-anchored protein ScaE. ScaA, -B, -C, and -E are all cohesin-bearing proteins encoded by linked genes in the sca cluster. The product of an unknown open reading frame within the sca cluster, herein designated CttA, is similar in sequence at its C terminus to the corresponding region of ScaB, which contains an X module together with a dockerin sequence. The ScaB-XDoc dyad was shown previously to interact tenaciously with the cohesin of ScaE. Likewise, avid binding was confirmed between purified recombinant fragments of the CttA-XDoc dyad and the ScaE cohesin. In addition, the N-terminal regions of CttA were shown to bind to cellulose, thus suggesting that CttA is a cell wall-anchored, cellulose-binding protein. Proteomic analysis showed that the native CttA protein ( approximately 130 kDa) corresponds to one of the three most abundant polypeptides binding tightly to insoluble cellulose in cellulose-grown R. flavefaciens 17 cultures. Interestingly, this protein was also detected among cellulose-bound proteins in the related strain R. flavefaciens 007C but not in a mutant derivative, 007S, that was previously shown to have lost the ability to grow on dewaxed cotton fibers. In R. flavefaciens, the presence of CttA on the cell surface is likely to provide an important mechanism for substrate binding, perhaps compensating for the absence of an identified cellulose-binding module in the major cellulosomal scaffolding proteins of this species.
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Affiliation(s)
- Marco T Rincon
- Microbial Ecology Group, The Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen, United Kingdom
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44
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Jindou S, Borovok I, Rincon MT, Flint HJ, Antonopoulos DA, Berg ME, White BA, Bayer EA, Lamed R. Conservation and divergence in cellulosome architecture between two strains of Ruminococcus flavefaciens. J Bacteriol 2006; 188:7971-6. [PMID: 16997963 PMCID: PMC1636321 DOI: 10.1128/jb.00973-06] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A 17-kb scaffoldin gene cluster in Ruminococcus flavefaciens strain FD-1 was compared with the homologous segment published for strain 17. Although the general design of the cluster is identical in the two strains, significant differences in the modular architecture of the scaffoldin proteins were discovered, implying strain-specific divergence in cellulosome organization.
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Affiliation(s)
- Sadanari Jindou
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
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45
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Hammel M, Fierobe HP, Czjzek M, Kurkal V, Smith JC, Bayer EA, Finet S, Receveur-Bréchot V. Structural Basis of Cellulosome Efficiency Explored by Small Angle X-ray Scattering. J Biol Chem 2005; 280:38562-8. [PMID: 16157599 DOI: 10.1074/jbc.m503168200] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cellulose, the main structural component of plant cell walls, is the most abundant carbohydrate polymer in nature. To break down plant cell walls, anaerobic microorganisms have evolved a large extracellular enzyme complex termed cellulosome. This megadalton catalytic machinery organizes an enzymatic assembly, tenaciously bound to a scaffolding protein via specialized intermodular "cohesin-dockerin" interactions that serve to enhance synergistic activity among the different catalytic subunits. Here, we report the solution structure properties of cellulosome-like assemblies analyzed by small angle x-ray scattering and molecular dynamics. The atomic models, generated by our strategy for the free chimeric scaffoldin and for binary and ternary complexes, reveal the existence of various conformations due to intrinsic structural flexibility with no, or only coincidental, inter-cohesin interactions. These results provide primary evidence concerning the mechanisms by which these protein assemblies attain their remarkable synergy. The data suggest that the motional freedom of the scaffoldin allows precise positioning of the complexed enzymes according to the topography of the substrate, whereas short-scale motions permitted by residual flexibility of the enzyme linkers allow "fine-tuning" of individual catalytic domains.
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Affiliation(s)
- Michal Hammel
- Architecture et Fonction des Macromolécules Biologiques, Unité Mixte de Recherche 6098, CNRS and Universities Aix-Marseille I and II, 163 Avenue de Luminy, Case 932, F-13288 Marseille Cedex 9, France
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46
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Barak Y, Handelsman T, Nakar D, Mechaly A, Lamed R, Shoham Y, Bayer EA. Matching fusion protein systems for affinity analysis of two interacting families of proteins: the cohesin-dockerin interaction. J Mol Recognit 2005; 18:491-501. [PMID: 16167300 DOI: 10.1002/jmr.749] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Cellulosomes are multi-enzyme complexes that orchestrate the efficient degradation of cellulose and related plant cell wall polysaccharides. The complex is maintained by the high-affinity protein-protein interaction between two complementary modules: the cohesin and the dockerin. In order to characterize the interaction between different cohesins and dockerins, we have developed matching fusion-protein systems, which harbor either the cohesin or the dockerin component. For this purpose, corresponding plasmid cassettes were designed, which encoded for the following carrier proteins: (i) a thermostable xylanase with an appended His-tag; and (ii) a highly stable cellulose-binding module (CBM). The resultant xylanase-dockerin and CBM-cohesin fusion products exhibited high expression levels of soluble protein. The expressed, affinity-purified proteins were extremely stable, and the functionality of the cohesin or dockerin component was retained. The fusion protein system was used to establish a sensitive and reliable, semi-quantitative enzyme-linked affinity assay for determining multiple samples of cohesin-dockerin interactions in microtiter plates. A variety of cohesin-dockerin systems, which had been examined previously using other methodologies, were revisited applying the affinity-based enzyme assay, the results of which served to verify the validity of the approach.
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Affiliation(s)
- Yoav Barak
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
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47
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Rincon MT, Cepeljnik T, Martin JC, Lamed R, Barak Y, Bayer EA, Flint HJ. Unconventional mode of attachment of the Ruminococcus flavefaciens cellulosome to the cell surface. J Bacteriol 2005; 187:7569-78. [PMID: 16267281 PMCID: PMC1280307 DOI: 10.1128/jb.187.22.7569-7578.2005] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2005] [Accepted: 08/24/2005] [Indexed: 11/20/2022] Open
Abstract
Sequence extension of the scaffoldin gene cluster from Ruminococcus flavefaciens revealed a new gene (scaE) that encodes a protein with an N-terminal cohesin domain and a C terminus with a typical gram-positive anchoring signal for sortase-mediated attachment to the bacterial cell wall. The recombinant cohesin of ScaE was recovered after expression in Escherichia coli and was shown to bind to the C-terminal domain of the cellulosomal structural protein ScaB, as well as to three unknown polypeptides derived from native cellulose-bound Ruminococcus flavefaciens protein extracts. The ScaB C terminus includes a cryptic dockerin domain that is unusual in its sequence, and considerably larger than conventional dockerins. The ScaB dockerin binds to ScaE, suggesting that this interaction occurs through a novel cohesin-dockerin pairing. The novel ScaB dockerin was expressed as a xylanase fusion protein, which was shown to bind tenaciously and selectively to a recombinant form of the ScaE cohesin. Thus, ScaE appears to play a role in anchoring the cellulosomal complex to the bacterial cell envelope via its interaction with ScaB. This sortase-mediated mechanism for covalent cell-wall anchoring of the cellulosome in R. flavefaciens differs from those reported thus far for any other cellulosome system.
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Affiliation(s)
- Marco T Rincon
- Microbial Ecology Group, Rowett Research Institute, Aberdeen, UK.
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48
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Abstract
Biomass conversion to ethanol as a liquid fuel by the thermophilic and anaerobic clostridia offers a potential partial solution to the problem of the world's dependence on petroleum for energy. Coculture of a cellulolytic strain and a saccharolytic strain of Clostridium on agricultural resources, as well as on urban and industrial cellulosic wastes, is a promising approach to an alternate energy source from an economic viewpoint. This review discusses the need for such a process, the cellulases of clostridia, their presence in extracellular complexes or organelles (the cellulosomes), the binding of the cellulosomes to cellulose and to the cell surface, cellulase genetics, regulation of their synthesis, cocultures, ethanol tolerance, and metabolic pathway engineering for maximizing ethanol yield.
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Affiliation(s)
- Arnold L Demain
- Charles A. Dana Research Institute for Scientists Emeriti, HS-330, Drew University, Madison, NJ 07940, USA.
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49
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Fierobe HP, Mingardon F, Mechaly A, Bélaïch A, Rincon MT, Pagès S, Lamed R, Tardif C, Bélaïch JP, Bayer EA. Action of designer cellulosomes on homogeneous versus complex substrates: controlled incorporation of three distinct enzymes into a defined trifunctional scaffoldin. J Biol Chem 2005; 280:16325-34. [PMID: 15705576 DOI: 10.1074/jbc.m414449200] [Citation(s) in RCA: 191] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In recent work, we reported the self-assembly of a comprehensive set of defined "bifunctional" chimeric cellulosomes. Each complex contained the following: (i) a chimeric scaffoldin possessing a cellulose-binding module and two cohesins of divergent specificity and (ii) two cellulases, each bearing a dockerin complementary to one of the divergent cohesins. This approach allowed the controlled integration of desired enzymes into a multiprotein complex of predetermined stoichiometry and topology. The observed enhanced synergy on recalcitrant substrates by the bifunctional designer cellulosomes was ascribed to two major factors: substrate targeting and proximity of the two catalytic components. In the present work, the capacity of the previously described chimeric cellulosomes was amplified by developing a third divergent cohesin-dockerin device. The resultant trifunctional designer cellulosomes were assayed on homogeneous and complex substrates (microcrystalline cellulose and straw, respectively) and found to be considerably more active than the corresponding free enzyme or bifunctional systems. The results indicate that the synergy between two prominent cellulosomal enzymes (from the family-48 and -9 glycoside hydrolases) plays a crucial role during the degradation of cellulose by cellulosomes and that one dominant family-48 processive endoglucanase per complex is sufficient to achieve optimal levels of synergistic activity. Furthermore cooperation within a cellulosome chimera between cellulases and a hemicellulase from different microorganisms was achieved, leading to a trifunctional complex with enhanced activity on a complex substrate.
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Affiliation(s)
- Henri-Pierre Fierobe
- Bioénergétique et Ingénierie des Protéines, CNRS, Institut de Biologie Structurale et Microbiologie, Marseille 13402, France.
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50
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Nakar D, Handelsman T, Shoham Y, Fierobe HP, Belaich JP, Morag E, Lamed R, Bayer EA. Pinpoint mapping of recognition residues on the cohesin surface by progressive homologue swapping. J Biol Chem 2004; 279:42881-8. [PMID: 15292269 DOI: 10.1074/jbc.m407350200] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The high affinity cohesin-dockerin interaction dictates the suprastructural assembly of the multienzyme cellulosome complex. The connection between affinity and species specificity was studied by exploring the recognition properties of two structurally related cohesin species of divergent specificity. The cohesins were examined by progressive rounds of swapping, in which corresponding homologous stretches were interchanged. The specificity of binding of the resultant chimeric cohesins was determined by enzyme-linked affinity assay and complementary protein microarray. In succeeding rounds, swapped segments were systematically contracted, according to the binding behavior of previously generated chimeras. In the fourth and final round we discerned three residues, reputedly involved in interspecies binding specificity. By replacing only these three residues, we were able to convert the specificity of the resultant mutated cohesin, which bound preferentially to the rival dockerin with approximately 20% capacity of the wild-type interaction. These residues represent but 3 of the 16 contact residues that participate in the cohesin-dockerin interaction. This approach allowed us to differentiate, in a structure-independent fashion, between residues critical for interspecies recognition and binding residues per se.
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Affiliation(s)
- David Nakar
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
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