洞察树纤维素合成酶-8的基质协调和葡萄糖转移
Preeti Verma1, Albert L Kwansa2, Ruoya Ho3
1Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22903, USA.
Structure (London, England : 1993)
|August 12, 2023
概括
研究人员从树中可视化了纤维素合成酶 (CesA8),揭示了UDP-葡萄糖如何结合,一个门环如何控制纤维素合成和穿过血的运输.
科学领域:
- 植物生物学 植物生物学
- 生物化学 生物化学
- 结构生物学 结构生物学
背景情况:
- 纤维素是植物细胞壁的主要结构成分.
- 纤维素合成酶 (CesA) 是一个膜集成的酶,负责纤维素生物合成.
- 切萨促进了聚合物在等离子膜上延长和转移.
研究的目的:
- 为了阐明混合青中纤维素合成酶 (CesA8) 的结构机制.
- 了解基质结合和在纤维素合成中的门环的作用.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于确定CesA8.8的基质和产品结合结构.
- 位点定向的突变发生,以调查门环的功能.
- 分子动力学模拟用于分析基质-蛋白相互作用.
主要成果:
- 获得同位三元CesA8.8的高分辨率冷EM结构.
- 在超膜通道附近的保存催化口袋内确定了UDP-葡萄糖结合.
- 突变性证实了门环在催化活性中的关键作用.
- 模拟显示,长时间的门环与基板相互作用对于定位至关重要.
结论:
- 门环对于调节纤维素合成和转位至关重要.
- 对CesA8的结构洞察力为了解植物细胞壁生物合成提供了基础.
- 这些发现有助于对流程性甘氨基基转移酶的知识.
相关概念视频
Role of Microtubules in Cell Wall Deposition
2.4K
Microtubules are small hollow tubes in eukaryotic cells. The cell wall microtubules are polymerized dimers of two globular proteins, α-tubulin and β-tubulin, two globular proteins. With a diameter of about 25 nm, microtubules are the widest components of the cytoskeleton. They help the cell resist compression and provide a track along which vesicles move through the cell or pull replicated chromosomes to opposite ends of a dividing cell. Microtubules go through quick cycles of...
2.4K
Cellulose and Pectic Polysaccharides
3.6K
Every plant cell has a cell wall that protects the cell, provides structural support, and gives the cell shape. Cellulose, the main structural component of the plant cell wall, makes up over 30% of plant matter. It is the most abundant organic compound on earth. Cellulose is an unbranched polysaccharide composed of linear chains of glucose molecules linked by β (1→4) glycosidic bonds.
As a cell matures, its cell wall specializes according to its type. For example, the...
As a cell matures, its cell wall specializes according to its type. For example, the...
3.6K
Oligosaccharide Assembly
2.9K
Protein glycosylation starts in the ER lumen and continues in the Golgi apparatus. Glycosyltransferases catalyze the addition of sugar molecules or glycosylation of proteins. Usually, these enzymes add sugars to the hydroxyl groups of selected serine or threonine residues to form O-linked glycans or the amino groups of asparagine residues to form N-linked glycans. Different positions on the same polypeptide chain can contain differently linked glycans.
Multiple sugar molecules that may or may...
Multiple sugar molecules that may or may...
2.9K
Biosynthesis of Polysaccharides
40
Polysaccharides such as glycogen and starch are synthesized from nucleoside diphosphate sugars, primarily uridine diphosphate glucose (UDPG) and adenosine diphosphate glucose (ADPG). These activated glucose donors act as key intermediates in carbohydrate metabolism and biosynthesis. UDPG primarily involves glycogen synthesis in animals and many bacteria, while ADPG plays a fundamental role in starch synthesis in plants and certain bacteria.UDPG is formed when glucose-1-phosphate reacts with...
40
Glycolysis: Preparatory Phase
13.7K
In cellular metabolism (the complete breakdown of glucose to extract energy), glycolysis is the first step. Glycolysis takes place in the cytoplasm of both prokaryotic and eukaryotic cells. Glucose enters heterotrophic cells in two ways. One method is through secondary active transport, where the transport takes place against the glucose concentration gradient. The other mechanism uses a group of integral proteins called GLUT proteins, also known as glucose transporter proteins. These...
13.7K
Cell Adhesion in Plants
2.7K
Plants have rigid cell walls that are made up of cell wall polysaccharides that mediate cell-cell adhesion. The primary cell walls of plants consist of two independent and interacting polysaccharide networks: a pectin matrix that embeds the second network comprising cellulose and hemicelluloses.
Pectins are complex heteropolymers mainly composed of negatively-charged α-D-glucopyranosyl uronic acid and some neutral glycosyl residues such as α-L-rhamnopyranose, α-L-arabinofuranose,...
Pectins are complex heteropolymers mainly composed of negatively-charged α-D-glucopyranosyl uronic acid and some neutral glycosyl residues such as α-L-rhamnopyranose, α-L-arabinofuranose,...
2.7K


