关于Aca7对促进者认可的结构性见解
So Yeon Lee1,2, Hyun Ho Park1,2
1College of Pharmacy, Chung-Ang University, Seoul, Korea.
The FEBS journal
|January 16, 2026
概括
反CRISPR相关 (Aca) 蛋白调节反CRISPR (Acr) 基因表达. 这项研究揭示了Aca7与DNA结合的结构,详细说明了它如何抑制Halomonas caseinilytica中的AcrIF11转录.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 遗传学 是一个遗传学.
背景情况:
- 克里斯普尔-卡斯系统为细菌提供了对菌体的适应性免疫力.
- 反CRISPR (Acr) 蛋白质是菌体编码的CRISPR-Cas. 的抑制剂.
- 反CRISPR相关 (Aca) 蛋白通过DNA结合来调节Acr的表达.
研究的目的:
- 为了识别和描述Aca7蛋白的DNA结合基因.
- 确定Aca7与其目标DNA结合的晶体结构.
- 阐明Aca7对AcrIF11转录抑制的分子机制.
主要方法:
- 在AcrIF11-Aca7操作子促进体中识别反向重复 (IR) DNA 基因.
- 进行X射线晶体学以确定Aca7-DNA复杂结构.
- 生物化学分析以确认特定序列的DNA结合.
主要成果:
- 首次鉴定了来自Halomonas caseinilytica的AcrIF11-Aca7促进体中的IR动机.
- 晶体结构显示了一个对称的Aca7二极体与IRDNA结合在一起.
- Aca7使用螺旋转螺旋图案进行主要沟结合,以及用于DNA曲的小沟接触.
- 特定的残留物 (R38,Q42,K46,K49) 对于序列识别至关重要.
结论:
- Aca7 特别识别并结合了 AcrIF11-Aca7 促进体中的 IR 元素.
- 该研究提供了Aca7介导的转录抑制的详细分子机制.
- 这些发现扩大了对Aca蛋白多样性和转录调节策略的理解.
相关概念视频
The Eukaryotic Promoter Region
18.7K
The eukaryotic promoter region is a segment of DNA located upstream of a gene. It contains an RNA polymerase binding site, a transcription start site, and several cis-regulatory sequences. The proximal promoter region is located in the vicinity of the gene and has cis-regulatory sequences and the core promoter. The core promoter is the binding site for RNA polymerase and is usually located between -35 and +35 nucleotides from the transcription start site. The distal promoter regions are...
18.7K
The Eukaryotic Promoter Region
3.8K
3.8K
Transcription Initiation
20.3K
Initiation is the first step of transcription in eukaryotes. Prokaryotic RNA Polymerase (RNAP) can bind to the template DNA and start transcribing. On the other hand, transcription in eukaryotes requires additional proteins, called transcription factors, to first bind to the promoter region in the DNA template. This binding helps recruit the specific RNAP that can assemble on the DNA and start transcription.
The promoters and enhancers and their accessory proteins allow tight regulation of...
The promoters and enhancers and their accessory proteins allow tight regulation of...
20.3K
Eukaryotic Transcription Activators
12.5K
Transcription activators are proteins that promote the transcription of genes from DNA to RNA. In most cases, these proteins contain two separate domains ‒ a domain that binds to DNA and a domain for activating transcription; however, in some cases, a single domain is responsible for both binding and activation of transcription, as seen in the glucocorticoid receptor and MyoD.
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These...
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These...
12.5K
RNA Polymerase II Accessory Proteins
10.8K
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
10.8K
RNA Polymerase II Accessory Proteins
3.8K
3.8K


