灵活性在酸性胺中:从E. coli胺中Asp43替代物的洞察力
Oanh Mai Ho1, Mohammed Shazaly A Elhassan1, Khang Nguyen1
1Department of Biomedical Science and Center for Bio-Nanomaterials, Daegu University, Gyeongsan 38453, South Korea.
Biochimica et biophysica acta. Proteins and proteomics
|November 21, 2025
概括
铁素 (Trxs) 通过43位的结构变化适应酸性条件. 用较小的氨基酸替换Asp43增加了灵活性,有助于氧化还原酶的酸性适应.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 酶学 是一种酶学.
背景情况:
- 铁素 (Trxs) 是关键的氧化还原酶,具有保留的CXXC活性位点.
- 了解Trx适应极端环境,如酸性条件至关重要.
- 对Trx适应酸性的结构机制尚不清楚.
研究的目的:
- 调查Asp43在大肠杆菌Trx (EcTrx) 稳定性和功能中的作用.
- 确定43位的氨基酸替代如何影响Trx适应酸性环境.
- 探索Trxs.中结构灵活性和酸性适应之间的关系.
主要方法:
- 在43位 (D43G,D43A,D43S,D43N,D43L,D43E) 的EcTrx的位点定向突变发生.
- 热转移测试和化诱导的展开,以评估蛋白质的稳定性.
- 催化活性测试 (DTNB) 用于评估酶功能.
- 对酸性Trxs. 的比较序列分析.
主要成果:
- 突变D43A和D43S的稳定性降低;D43G保持了适度的稳定性,增加了灵活性.
- D43N和D43L通过极性或疏水性相互作用赋予了部分稳定.
- D43E,模仿祖先的残留物,增强了热稳定性和刚性.
- 大多数突变保留了催化活性,除了D43S (50%的野生类型活性).
结论:
- Asp43对于保持EcTrx结构稳定性至关重要.
- 在位置43的增强,但不过度的灵活性,有助于Trx适应酸性环境.
- 在位置43的结构修改是Trxs在酸性条件下的功能适应的关键.
更多相关视频
相关概念视频
Diversity of Archaea III
304
Crenarchaeota, a prominent phylum of Archaea, is remarkable for its ability to thrive in extreme environments characterized by high temperatures and acidity. These microorganisms inhabit sulfuric hot springs, volcanic systems, and submarine hydrothermal vents, where temperatures often exceed 100°C. The unique adaptations of Crenarchaeota not only allow survival under such extreme conditions but also provide insights into the mechanisms of life in primordial Earth-like...
304
Protein Modifications in the RER
6.8K
Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal...
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal...
6.8K
Diversity of Archaea IV
381
Hyperthermophilic archaea are a group of extremophiles thriving at temperatures above 80°C, often in hydrothermal vents and volcanic soils where conditions surpass the boiling point of water. At such temperatures, proteins, membranes, and DNA in most organisms degrade, but hyperthermophiles have evolved remarkable adaptations to maintain stability and function.Unique Cellular FeaturesHyperthermophilic membranes are composed of a monolayer of biphytanyl tetraether lipids, which resist...
381
Sulfur Assimilation
302
Sulfur is an essential element in biological systems, contributing to synthesizing key biomolecules, including amino acids such as cysteine and methionine, and cofactors such as coenzyme A and biotin. Microorganisms primarily assimilate sulfur as sulfate (SO₄²⁻) from the environment, which must undergo a series of biochemical transformations before it can be incorporated into cellular components. As sulfate is highly oxidized, it must undergo assimilatory sulfate reduction to...
302
Other Stress Responses in Bacteria
318
Bacteria have global regulatory systems that control several types of stress mechanisms. These include Pho regulon and the heat shock response, which are essential systems for environmental adaptation, such as nutrient limitation and proteotoxic stress. The Pho regulon and the heat shock response exemplify bacterial resilience, enabling rapid adaptation to fluctuating environmental conditions.Pho RegulonBacteria require phosphorus for essential cellular processes, including nucleic acid...
318
Intrinsically Disordered Proteins
19.2K
Intrinsically disordered proteins are a group of proteins that do not fold into specific three-dimensional structures. Their structural flexibility allows them to complement ordered proteins to perform functions that are inaccessible to rigid structures. They are more common in eukaryotes than prokaryotes and may either be exclusively intrinsically disordered or hybrid proteins, consisting of a mix of ordered and disordered regions. The absence of a rigid structure in these proteins can be...
19.2K


