Related Experiment Video
Updated: May 20, 2026
09:40
Phage Phenomics: Physiological Approaches to Characterize Novel Viral Proteins
Published on: June 11, 2015
Expression and functional characterization of the first bacteriophage-encoded chaperonin
Lidia P Kurochkina1, Pavel I Semenyuk, Victor N Orlov
1Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia. lpk@ibch.ru.
Journal of Virology
|July 13, 2012
Summary
Researchers characterized the first viral chaperonin, gp146, from bacteriophage EL. This protein aids in protein folding, similar to bacterial GroEL, but functions independently of cochaperonins.
Area of Science:
- Molecular Biology
- Virology
- Protein Biochemistry
Background:
- Chaperonins are essential molecular chaperones that assist protein folding in all domains of life.
- Bacteriophage EL encodes a protein, gene product 146 (gp146), identified as a potential viral chaperonin and GroEL ortholog.
Purpose of the Study:
- To express and characterize the recombinant viral chaperonin gp146 for the first time.
- To identify the native substrate of gp146 and confirm its chaperonin function in vitro.
Main Methods:
- Recombinant expression of gp146 in Escherichia coli.
- Physicochemical characterization of recombinant gp146.
- Immunoprecipitation using anti-gp146 serum to identify the native substrate (gp188 endolysin) via mass spectrometry.
- In vitro assays to assess gp146's effect on endolysin thermal stability and aggregation.
Main Results:
- Recombinant gp146 was successfully expressed and characterized.
- The phage endolysin gp188 was identified as the native substrate of gp146.
- gp146 demonstrated protective effects against thermal inactivation and aggregation of gp188, confirming its chaperonin activity.
- gp146 shares structural and functional similarities with GroEL but does not require a cochaperonin.
Conclusions:
- gp146 represents the first identified viral chaperonin with functions analogous to cellular GroEL.
- This viral chaperonin plays a role in the propagation of bacteriophage EL by stabilizing its endolysin.
- The functional independence from cochaperonins distinguishes gp146 from some cellular chaperonin systems.
Related Concept Videos
01:26DNA Bacteriophages
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...
03:00Molecular Chaperones and Protein Folding
The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein.
The...
The...
03:00Molecular Chaperones and Protein Folding
The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein.
The...
The...
01:30Lytic 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 lytic replication...
00:43Lysogenic 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...
01:26Bacterial Protein Maturation
Bacterial protein maturation is a tightly regulated process that ensures newly synthesized polypeptides achieve correct functional conformations. This maturation involves a series of modifications, folding events, and quality control steps, often assisted by specialized chaperone proteins.N-Terminal ModificationsThe maturation of bacterial polypeptides begins cotranslationally as the polypeptide exits the ribosome. The first amino acid, N-formylmethionine (fMet), is typically modified at the...