模块化聚胺合成酶包含两个异步运行的反应室
Saket R Bagde1,2, Irimpan I Mathews3, J Christopher Fromme2
1Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, TX 79968, USA.
Science (New York, N.Y.)
|November 4, 2021
概括
对I型模块化聚化酶 (PKS) 的结构洞察力揭示了Lsd14 PKS如何使用两个反应室,一次只能有一个主动产生聚化物产物.
科学领域:
- 生物化学
- 结构生物学
- 酵素学
背景情况:
- I型模块化聚化酶 (PKS) 是大型的多域酶,对于合成各种聚化天然产品至关重要.
- 这些酶作为组装线,催化序列链延伸和修饰反应.
研究的目的:
- 阐明I型模块化多基合成酶的结构机制.
- 了解Lsd14 PKS在催化周期中的域定位,重新排列和相互作用.
主要方法:
- 在2.4安格斯特罗姆分辨率下确定了Lsd14 PKS的X射线晶体结构.
- 在3.1安格斯特罗姆分辨率下确定了Lsd14PKS的冷电子显微镜结构,捕获了不同的反应状态.
主要成果:
- 揭示了 Lsd14 PKS 中域的精确定位和动态重新排列.
- 确定了对酶功能至关重要的特定域间相互作用.
- 证明Lsd14PKS具有两个反应室,但在任何给定时间只有一个用于产品合成的催化活性.
结论:
- 该研究提供了I型模块化PKS功能的详细结构理解.
- Lsd14 PKS表现出一种独特的机制,涉及其两个反应室的不对称利用.
- 这些发现提供了关于多基生物合成和酶进化的见解.
相关概念视频
02:31Multi-Step Reactions
7.7K
Chemical reactions often occur in a stepwise fashion involving two or more distinct reactions taking place in a sequence. A balanced equation indicates the reacting species and the product species, but it reveals no details about how the reaction occurs at the molecular level. The reaction mechanism (or reaction path) provides details regarding the precise, step-by-step process by which a reaction occurs. Each of the steps in a reaction mechanism is called an elementary reaction. These...
7.7K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.5K
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.5K
01:26Photochemical Electrocyclic Reactions: Stereochemistry
1.9K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
1.9K
01:58Cooperative Allosteric Transitions
8.2K
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
8.2K
01:29Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
4.9K
Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.
4.9K
01:28Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
4.2K
The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.
4.2K