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Cho SH, Purushotham P, Fang C, Maranas C, Díaz-Moreno SM, Bulone V, Zimmer J, Kumar M, Nixon BT. Synthesis and Self-Assembly of Cellulose Microfibrils from Reconstituted Cellulose Synthase. Plant Physiol 2017; 175:146-156. [PMID: 28768815 PMCID: PMC5580757 DOI: 10.1104/pp.17.00619] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 07/29/2017] [Indexed: 05/04/2023]
Abstract
Cellulose, the major component of plant cell walls, can be converted to bioethanol and is thus highly studied. In plants, cellulose is produced by cellulose synthase, a processive family-2 glycosyltransferase. In plant cell walls, individual β-1,4-glucan chains polymerized by CesA are assembled into microfibrils that are frequently bundled into macrofibrils. An in vitro system in which cellulose is synthesized and assembled into fibrils would facilitate detailed study of this process. Here, we report the heterologous expression and partial purification of His-tagged CesA5 from Physcomitrella patens Immunoblot analysis and mass spectrometry confirmed enrichment of PpCesA5. The recombinant protein was functional when reconstituted into liposomes made from yeast total lipid extract. The functional studies included incorporation of radiolabeled Glc, linkage analysis, and imaging of cellulose microfibril formation using transmission electron microscopy. Several microfibrils were observed either inside or on the outer surface of proteoliposomes, and strikingly, several thinner fibrils formed ordered bundles that either covered the surfaces of proteoliposomes or were spawned from liposome surfaces. We also report this arrangement of fibrils made by proteoliposomes bearing CesA8 from hybrid aspen. These observations describe minimal systems of membrane-reconstituted CesAs that polymerize β-1,4-glucan chains that coalesce to form microfibrils and higher-ordered macrofibrils. How these micro- and macrofibrils relate to those found in primary and secondary plant cell walls is uncertain, but their presence enables further study of the mechanisms that govern the formation and assembly of fibrillar cellulosic structures and cell wall composites during or after the polymerization process controlled by CesA proteins.
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Affiliation(s)
- Sung Hyun Cho
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Pallinti Purushotham
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia 22908
| | - Chao Fang
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Cassandra Maranas
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98105
| | - Sara M Díaz-Moreno
- Division of Glycoscience, School of Biotechnology, Royal Institute of Technology (KTH), Stockholm, SE-10691, Sweden
| | - Vincent Bulone
- Division of Glycoscience, School of Biotechnology, Royal Institute of Technology (KTH), Stockholm, SE-10691, Sweden
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of Agriculture, Food and Wine, University of Adelaide, Urrbrae 5064, South Australia, Australia
| | - Jochen Zimmer
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia 22908
| | - Manish Kumar
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - B Tracy Nixon
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
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Maranas C, Androulakis I, Floudas C. A deterministic global optimization approach
for the protein folding problem. Global Minimization of Nonconvex Energy
Functions: Molecular Conformation and Protein
Folding 1995. [DOI: 10.1090/dimacs/023/09] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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