Related Experiment Video
Updated: Jul 31, 2025
09:44
Characterization of a Pathogenic Escherichia coli Strain Derived from Oreochromis spp. Farms Using Whole-Genome Sequencing
Published on: December 23, 2022
2.2K
Structural and functional features of a broad-spectrum prophage-encoded enzybiotic from Enterococcus faecium
Georgios E Premetis1, Angeliki Stathi2, Anastassios C Papageorgiou3
1Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, 11855, Athens, Greece.
Scientific Reports
|May 8, 2023
Summary
Researchers identified a novel enzyme, EfAmi1, from Enterococcus faecium with potent antimicrobial activity. This peptidoglycan-degrading enzyme shows promise as a new therapeutic agent against multidrug-resistant bacteria in the post-antibiotic era.
Area of Science:
- Microbiology
- Biochemistry
- Structural Biology
Background:
- Multidrug-resistant (MDR) bacteria, particularly Gram-positive Enterococcus faecium, pose a significant global public health threat.
- Peptidoglycan-degrading enzymes (PDEs), or enzybiotics, are emerging as crucial bactericidal agents against antibiotic-resistant pathogens.
- E. faecium is a WHO-classified high-priority pathogen, necessitating novel therapeutic strategies.
Purpose of the Study:
- To identify and characterize novel peptidoglycan-degrading enzymes (PDEs) from E. faecium with antimicrobial potential.
- To investigate the lytic and antimicrobial activities of the identified enzyme, EfAmi1.
- To determine the crystal structure of the N-terminal domain of EfAmi1 for mechanistic insights.
Main Methods:
- Genome-based screening of E. faecium to identify putative PDE genes.
- Cloning, expression, and purification of the full-length EfAmi1 protein in E. coli.
- Turbidity reduction and Kirby-Bauer disk-diffusion assays to evaluate lytic and antimicrobial activity.
- X-ray crystallography to determine the structure of the N-terminal amidase-2 domain.
Main Results:
- Identification of a novel putative PDE gene, EfAmi1, encoding a Zn2+-dependent N-acetylmuramoyl-L-alanine amidase-2 (NALAA-2) domain.
- EfAmi1 was successfully expressed as a soluble, purified 6xHis-tagged protein.
- Demonstrated high lytic and antimicrobial activity against clinically relevant bacterial pathogens.
- The crystal structure of the N-terminal domain revealed a globular fold with a putative zinc-binding site.
Conclusions:
- EfAmi1 exhibits significant lytic and antimicrobial properties, highlighting its potential as a novel therapeutic agent.
- The structural characterization provides insights into the enzyme's mechanism of action.
- EfAmi1 represents a promising candidate for combating infections caused by multidrug-resistant bacteria in the post-antibiotic era.
Related Concept Videos
01:26DNA Bacteriophages
69
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...
69
01:20Viral Replication: Lytic Cycle
98
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...
98
01:16Viral Replication: Lysogenic Cycle
93
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...
93
00:43Lysogenic Cycle of Bacteriophages
62.7K
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...
62.7K
01:26Bacterial Phylum Verrucomicrobiota
47
The phylum Verrucomicrobiota comprises at least four characterized orders, with most species classified within the order Verrucomicrobiotales. Members of this phylum are either aerobic or facultatively aerobic, with the ability to ferment sugars. A notable exception is the genus Methylacidiphilum, which consists of aerobic methanotrophs. Additionally, some Verrucomicrobiota establish symbiotic relationships with protists. These bacteria are widely distributed across various environments,...
47
01:30Lytic Cycle of Bacteriophages
71.3K
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...
71.3K