肺炎链球菌 (Streptococcus pneumoniae) HtrA是一种动态和单体毒性因子,能够形成更大的寡合复合体
Eunjeong Lee1, Jasmina S Redzic1, Blaine Gordon1
1Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, Colorado, USA.
Protein science : a publication of the Protein Society
|December 29, 2025
概括
这项研究揭示了Streptococcus pneumoniae高温要求A (HtrA) 作为一个动态单体而起作用,与典型的HtrA结构不同. 这一发现突显了格拉姆阳性细菌对蛋白质质量控制的独特机制.
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:
- 高温要求的A (HtrA) 蛋白酶对于蛋白质质量控制和细菌中的毒性至关重要.
- 虽然已知格兰阴性细菌和人类的HtrA结构,但对格兰阳性HtrA同类的了解很少.
研究的目的:
- 为了进行第一个综合结构和机械分析的Gram-阳性HtrA从Streptococcus pneumoniae.进行第一个综合结构和机械分析.
- 阐明S. pneumoniae HtrA在蛋白质质量控制中的作用及其结构特征.
主要方法:
- 一个htrA淘汰菌株的蛋白质组概况.
- 在体外切割试验.
- 生物化学表征 (单体/三元体分析).
- 核磁共振 (NMR) 光谱学.核磁共振 (NMR) 光谱学.
- 低温电子显微镜 (低温电子显微镜).
主要成果:
- S. pneumoniae HtrA对于蛋白质质量控制至关重要,其PDZ域介导基质识别.
- 与传统的HtrA不同,S. pneumoniae的HtrA仅作为溶液中的单体存在,这种特征与其他Gram阳性同类物共享.
- 核磁共振揭示了单体中的动态构造采样,而冷-EM确定了一个由新的LoopA-PDZ相互作用稳定起来的六合体.
结论:
- 在S. pneumoniae中,HtrA作为具有合蛋白酶和PDZ域的动态单体而起作用.
- 格拉姆阳性HtrA代表了HtrA家族内机械上不同的亚组,与它们的格拉姆阴性和人类对应物分开.
更多相关视频
06:06Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43
Published on: September 11, 2020
2.0K
12:21A Mouse Model for the Transition of Streptococcus pneumoniae from Colonizer to Pathogen upon Viral Co-Infection Recapitulates Age-Exacerbated Illness
Published on: September 28, 2022
3.0K
相关概念视频
02:41Protein Complex Assembly
16.5K
Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes.
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Many viruses self-assemble into a fully functional unit using the infected host cell to...
16.5K
01:19Mechanism of Conjugation
717
Bacterial conjugation is a mechanism of horizontal gene transfer that enables the exchange of genetic material between bacterial cells through direct contact. This process is facilitated by a donor cell carrying a conjugative plasmid, which encodes genes necessary for pilus formation, DNA replication, and transfer. The conjugative plasmid plays a central role in initiating and executing the transfer of genetic material.The tra region of the conjugative plasmid encodes proteins responsible for...
717
01:28Fimbriae, Pili, and Axial Filaments
1.4K
Fimbriae and pili are specialized bacterial surface structures that play pivotal roles in adhesion, genetic exchange, and motility. Composed primarily of pilin protein, these hairlike appendages are crucial for bacterial survival and pathogenicity in various environments.Fimbriae: Adhesion and PathogenicityFimbriae are fine, filamentous structures measuring 2–10 nanometers in diameter and are densely distributed on the bacterial cell surface. They facilitate bacterial adhesion to abiotic...
1.4K
01:57Protein Complexes with Interchangeable Parts
2.8K
Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order...
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order...
2.8K
01:19Formation of Lipopolysaccharides
486
Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin,...
486
01:24Adherens Junctions
6.1K
Strong contact points between adjacent cells anchor them to each other, forming tissues. Such anchoring junctions are of two types – adherens junctions and desmosomes. Adherens junctions are abundant in tissues such as epithelium and endothelium, forming a continuous zone of adhesion called the adhesion belt. In other tissues, such as heart muscle, they appear as clusters, linking the cells to produce coordinated heart muscle contraction.
Adherens Junctions are Dynamic
Adherens Junctions are Dynamic
6.1K