菌体T4的尖端蛋白
bioRxiv : the preprint server for biology
|September 5, 2025
概括
收缩注射系统使用管机制透细胞. 细菌体T4
科学领域:
- 微生物学
- 分子生物学
- 结构生物学
背景情况:
- 收缩注射系统 (CIS),包括菌体尾巴和细菌类型VI分泌系统,是将效应物送入细胞的分子机器.
- CIS使用可收缩的外和刚性管穿透细胞外,在攻击膜的末端有一个尖复合体.
研究的目的:
- 研究尖蛋白在菌体T4感染中的作用.
- 确定编码菌体T4尖端蛋白的基因.
主要方法:
- 在不同菌体中对CIS结构进行比较分析.
- 使用珀无意义突变进行定位突变.
- 细菌感染测定,包括细菌显示截断的脂多糖.
主要成果:
- 在菌体P2中,尖和尖的蛋白质被合并,膜收缩将尖转移到周围质中.
- 菌体T4中的ORFan基因为尖端蛋白 (gp5.4) 编码.
- gp5.4 对于菌体组合并不重要,但对于菌体T4 适应性和特定细菌菌株的感染至关重要.
结论:
- 这项研究阐明了不同细菌菌体中尖端蛋白的独特遗传组织.
- 鉴定了一种新型的细菌T4感染必需蛋白质,强调其在克服细菌防御中的作用.
- 提供了CIS介导细胞进入和宿主特异性的机制.
相关概念视频
DNA Bacteriophages
138
Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...
138
Viral Replication: Lytic Cycle
209
Bacteriophages, or phages, are viruses that specifically infect bacteria. Among them, T-even bacteriophages, such as T4, exhibit a well-characterized lytic replication cycle in Escherichia coli (E. coli). This process ensures the rapid proliferation of the virus while ultimately leading to the destruction of the bacterial host.Attachment and DNA InjectionThe infection process begins with the recognition and binding of the T4 phage to the E. coli cell surface. Tail fibers of the phage...
209
Lytic Cycle of Bacteriophages
71.9K
Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the...
71.9K
Lysogenic Cycle of Bacteriophages
63.1K
In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
63.1K
Viral Structure
63.5K
Viruses are extraordinarily diverse in shape and size, but they all have several structural features in common. All viruses have a core that contains a DNA- or RNA-based genome. The core is surrounded by a protective coat of proteins called the capsid. The capsid is composed of subunits called capsomeres. The capsid and genome-containing core are together known as the nucleocapsid.
63.5K
Viral Replication: Lysogenic Cycle
202
The lysogenic cycle is a crucial viral replication strategy that allows bacteriophages to persist within host cells without immediately destroying them. This process is primarily observed in temperate phages, such as bacteriophage lambda (λ), which infects Escherichia coli. The cycle allows the viral genome to persist across bacterial generations while keeping host cells viable.Integration of the Viral GenomeUpon infection, bacteriophage lambda attaches to the bacterial surface and injects...
202


