对细菌UDP-糖2-表皮酶的结构分析揭示了催化前后活性位点的结构
James B Thoden1, James O McKnight1, Charles W Kroft1
1Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA.
The Journal of biological chemistry
|September 3, 2023
概括
这项研究特征了一种来自热友Thermus thermophilus的新型2-epimerase,揭示了其独特的基质结合和通过UDP-N-乙-d-葡萄糖胺 (UDP-GlcNAc) 的全调节. 这为极端环境中糖生物合成途径提供了新的见解.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 微生物学 微生物学
背景情况:
- 糖2,3-二甲胺-2,3-二氧化-d-曼努龙酸在各种病原性格拉姆阴性细菌的O-抗原中发现.
- 它的生物合成涉及五种酶,最后一步由作用于UDP-2,3-diacetamido-2,3-dideoxy-d-glucuronic acid的2-epimerase催化.
- 这种途径在极端热爱动物中的存在仍然未被探索.
研究的目的:
- 为了研究参与2,3-diacetamido-2,3-dideoxy-d-mannuronic acid在极端热爱型Thermus thermophilus HB27中的生物合成中的酶的存在和功能.
- 为了描述负责该途径的最后一步的特定2 - epimerase (ORF WP_011172736).
- 阐明这种酶的基质结合和全调节的结构基础.
主要方法:
- 对Thermus thermophilus HB27基因组进行生物信息分析,以确定潜在的ORF.
- 高分辨率的X射线晶体学 (10个结构),以确定酶的三维结构.
- 生物化学试验用于研究基质结合,产品定和全调节.
主要成果:
- 在T. thermophilus HB27中识别了五个ORF,这些ORF可能对该途径编码酶,WP_011172736被证实为2-epimerase.
- X射线晶体结构揭示了酶如何在活性部位结合其UDP-糖基质和产物.
- 通过UDP-N-乙-d-葡萄糖胺 (UDP-GlcNAc) 证明了UDP-糖在活性部位和异质部位的同时结合,以及异质部位的调节.
结论:
- 这项研究提供了第一个详细的结构和生化研究,使用UDP-2,3-diacetamido-2,3-dideoxy-d-glucuronic acid作为基质的2-epimerase.
- 在Thermus thermophilus的2-epimerase表现出独特的基质定和性调节机制.
- 这项工作扩大了我们对极端友好生物体中碳水化合物生物合成途径的理解.
关键词:
2,3-二甲胺-2,3-二氧化-d-曼努龙酸的二,3-二甲胺-2,3-二氧化-d-曼努龙酸.这是一种O-抗原.细菌 细菌 细菌是一种细菌.碳水化合物是一种碳水化合物.结晶学 结晶学是指结晶学.酶结构 酶结构脂多糖类糖化物 (Lipopolysaccharide) 是一种脂多糖类糖.更多相关视频
13:35Structural Biology and Analytical Chemistry Approaches for Characterizing C-Glycoside Metabolic Enzymes in Human Gut Microbiota
Published on: May 23, 2025
470
12:19Uracil-DNA Glycosylase Assay by Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry Analysis
Published on: April 22, 2022
3.9K
相关概念视频
Enzymes
81.8K
Inside living organisms, enzymes act as catalysts for many biochemical reactions involved in cellular metabolism. The role of enzymes is to reduce the activation energies of biochemical reactions by forming complexes with its substrates. The lowering of activation energies favor an increase in the rates of biochemical reactions.
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
81.8K
Introduction to Mechanisms of Enzyme Catalysis
8.3K
For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes...
8.3K
Catalytically Perfect Enzymes
4.0K
The theory of catalytically perfect enzymes was first proposed by W.J. Albery and J. R. Knowles in 1976. These enzymes catalyze biochemical reactions at high-speed. Their catalytic efficiency values range from 108-109 M-1s-1. These enzymes are also called 'diffusion-controlled' as the only rate-limiting step in the catalysis is that of the substrate diffusion into the active site. Examples include triose phosphate isomerase, fumarase, and superoxide dismutase.
Most enzymes...
Most enzymes...
4.0K
Allosteric Proteins-ATCase
5.8K
Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis...
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis...
5.8K
ATP Synthase: Mechanism
14.8K
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased...
14.8K
Peptidoglycan Synthesis
54
Structure of PeptidoglycanPeptidoglycan is a vital structural component of the bacterial cell wall, providing mechanical strength and shape to the cell. It consists of repeating units of two sugars—N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)—linked by β-1,4 glycosidic bonds. These sugar chains are cross-linked by short peptide chains, forming a mesh-like polymer that surrounds the bacterial plasma membrane.Cytoplasmic Phase – Precursor SynthesisPeptidoglycan...
54
