The pattern of xylan acetylation suggests xylan may interact with cellulose microfibrils as a twofold helical screw in the secondary plant cell wall of Arabidopsis thaliana.
The pattern of xylan acetylation suggests xylan may interact with cellulose microfibrils as a twofold helical screw in the secondary plant cell wall of Arabidopsis thaliana.
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DOI：
10.1111/tpj.12575
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发表时间：
2014-08
期刊：
影响因子：
--
通讯作者：
Dupree P
中科院分区：
文献类型：
--
作者：
Busse-Wicher M;Gomes TC;Tryfona T;Nikolovski N;Stott K;Grantham NJ;Bolam DN;Skaf MS;Dupree P
木聚糖和纤维素微纤丝之间的相互作用对于维管植物中次生细胞壁的性质是重要的;然而，木聚糖在细胞壁中的分子排列和多糖之间的分子键合的性质是未知的。在双子叶植物中，β-（1，4）-连接的木糖残基的木聚糖主链偶尔被葡萄糖醛酸修饰，并且大约一半的木糖残基在C-2或C-3处被O-乙酰化。我们最近提出，双子叶木聚糖的主要结构域中GlcA残基的均匀、周期性间隔可能允许木聚糖主链折叠为双重螺旋，以促进沿着排列，并与纤维素原纤维稳定相互作用;然而，这种相互作用可能受到木聚糖主链的随机乙酰化的不利影响。在这里，我们研究了拟南芥木聚糖乙酰基残基的安排，使用质谱和核磁共振。沿着主链的交替木糖残基沿着被乙酰化。利用分子动力学模拟，我们发现木聚糖的双螺旋螺旋构象在与亲水和疏水纤维素表面的相互作用中是稳定的。紧密对接的木聚糖的亲水面是可行的，只有木聚糖装饰在交替的残基和折叠作为一个双重的螺旋螺丝。这些发现表明了乙酰化对木聚糖-纤维素相互作用的重要性的解释，并且也对我们理解细胞壁分子结构和性质以及病原体和真菌的生物降解具有影响。它们还将影响改善木质纤维素生物精炼和生物能源加工的战略。
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 β-(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.
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影响因子：
7.2
作者：
Bromley, Jennifer R.;Busse-Wicher, Marta;Dupree, Paul
通讯作者：
Dupree, Paul
影响因子：
7.4
作者：
Manabe, Yuzuki;Nafisi, Majse;Scheller, Henrik Vibe
通讯作者：
Scheller, Henrik Vibe
影响因子：
7.4
作者：
Manabe, Yuzuki;Verhertbruggen, Yves;Scheller, Henrik Vibe
通讯作者：
Scheller, Henrik Vibe
影响因子：
5.5
作者：
Guvench, Olgun;Hatcher, Elizabeth;Venable, Richard M.;Pastor, Richard W.;MacKerell, Alexander D., Jr.
通讯作者：
MacKerell, Alexander D., Jr.
影响因子：
3.7
作者：
Lefebvre V;Fortabat MN;Ducamp A;North HM;Maia-Grondard A;Trouverie J;Boursiac Y;Mouille G;Durand-Tardif M
通讯作者：
Durand-Tardif M