相关实验视频

Updated: Jun 6, 2025

Following Cell-fate in E. coli After Infection by Phage Lambda

Following Cell-fate in E. coli After Infection by Phage Lambda

Published on: October 14, 2011

揭穿了RecBCD核酶破坏菌体的教条

Clarence Zheng¹, Curtis Furukawa², Jerry Liu³

¹Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA.

|November 28, 2024

概括

细菌的RecBCD酶 (外核酶V) 不像声称的那样破坏外来菌体. 相反,RecBCD可以修复可重组的破损DNA,并从无法重组的DNA中回收核酸.

科学领域:

分子生物学分子生物学
细菌学细菌学是一门学科.
病毒学病毒学

背景情况:

细菌的RecBCD酶,也称为外核酶V,被广泛认为通过降解外来DNA来保护宿主,例如菌体.
这种声称的功能表明宿主生存机制涉及自我和非自我DNA之间的歧视.
然而,在以前的权利要求中,没有确定RecBCD向的特定菌体.

研究的目的:

实证地确定哪些细菌,如果有的话,被RecBCD酶摧毁.
调查关于RecBCD在降解外来DNA中的作用的长期声称的准确性.

主要方法:

选超过160个细菌菌体分离物 (80+新,80+来自采集) 以检测它们在具有或没有功能性RecBCD的*Escherichia coli*菌株上生长的能力.
隔离可能在缺乏RecBCD (ΔrecBCD) 的大肠杆菌上传播的菌体,但不能在野生型的recBCD+*上传播的菌体.

主要成果:

没有发现与recBCD+*菌株相比,只在*大肠杆菌* ΔrecBCD上生长的细菌菌分离物.
这一发现直接违背了普遍的假设,即RecBCD积极破坏外来菌体DNA.

结论:

该研究得出的结论是,RecBCD并没有像之前所说的那样不分青红白地破坏外来菌体DNA.
RecBCD的主要功能似乎是修复能够重组的破损DNA.
该酶可能会降解无法重组的DNA,从而促进宿主细胞的核酸循环.

关键词:

美国大肠杆菌 (E. coli).在RecBCD中,基酶-核酶是基酶-核酶.环境菌体环境菌体菌体破坏教条的教条

更多相关视频

Understanding the Impact of Temperate Bacteriophages on Their Lysogens Through Transcriptomics

Understanding the Impact of Temperate Bacteriophages on Their Lysogens Through Transcriptomics

Published on: January 5, 2024

Phage-Mediated Genetic Manipulation of the Lyme Disease Spirochete Borrelia burgdorferi

Phage-Mediated Genetic Manipulation of the Lyme Disease Spirochete Borrelia burgdorferi

Published on: September 28, 2022

相关概念视频

Lysogenic Cycle of Bacteriophages

Lysogenic Cycle of Bacteriophages

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...

Lytic Cycle of Bacteriophages

Lytic Cycle of Bacteriophages

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...

Viral Replication: Lysogenic Cycle

Viral Replication: Lysogenic Cycle

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...

Viral Replication: Lytic Cycle

Viral Replication: Lytic Cycle

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...

CRISPR and crRNAs

CRISPR and crRNAs

Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea.
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...

Restarting Stalled Replication Forks

Restarting Stalled Replication Forks

DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart,...