| Full text | |
| Author(s): |
Busse-Wicher, Marta
[1]
;
Gomes, Thiago C. F.
[2]
;
Tryfona, Theodora
[1]
;
Nikolovski, Nino
[1]
;
Stott, Katherine
[1]
;
Grantham, Nicholas J.
[1]
;
Bolam, David N.
[3]
;
Skaf, Munir S.
[2]
;
Dupree, Paul
[1]
Total Authors: 9
|
| Affiliation: | [1] Univ Cambridge, Dept Biochem, Cambridge CB2 1QW - England
[2] Univ Estadual Campinas, UNICAMP, Inst Chem, BR-13084862 Campinas, SP - Brazil
[3] Newcastle Univ, Sch Med, Inst Cell & Mol Biosci, Newcastle Upon Tyne NE2 4HH, Tyne & Wear - England
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | Plant Journal; v. 79, n. 3, p. 492-506, AUG 2014. |
| Web of Science Citations: | 94 |
| Abstract | |
The interaction between xylan and cellulose microfibrils is important for secondary cell wall properties in vascular plants; however, the molecular arrangement of xylan in the cell wall and the nature of the molecular bonding between the polysaccharides are unknown. In dicots, the xylan backbone of beta-(1,4)-linked xylosyl residues is decorated by occasional glucuronic acid, and approximately one-half of the xylosyl residues are O-acetylated at C-2 or C-3. We recently proposed that the even, periodic spacing of GlcA residues in the major domain of dicot xylan might allow the xylan backbone to fold as a twofold helical screw to facilitate alignment along, and stable interaction with, cellulose fibrils; however, such an interaction might be adversely impacted by random acetylation of the xylan backbone. Here, we investigated the arrangement of acetyl residues in Arabidopsis xylan using mass spectrometry and NMR. Alternate xylosyl residues along the backbone are acetylated. Using molecular dynamics simulation, we found that a twofold helical screw conformation of xylan is stable in interactions with both hydrophilic and hydrophobic cellulose faces. Tight docking of xylan on the hydrophilic faces is feasible only for xylan decorated on alternate residues and folded as a twofold helical screw. The findings suggest an explanation for the importance of acetylation for xylan-cellulose interactions, and also have implications for our understanding of cell wall molecular architecture and properties, and biological degradation by pathogens and fungi. They will also impact strategies to improve lignocellulose processing for biorefining and bioenergy. (AU) | |
| FAPESP's process: | 13/08293-7 - CCES - Center for Computational Engineering and Sciences |
| Grantee: | Munir Salomao Skaf |
| Support Opportunities: | Research Grants - Research, Innovation and Dissemination Centers - RIDC |