Related Experiment Video

Updated: Apr 17, 2026

MS2-Affinity Purification Coupled with RNA Sequencing in Gram-Positive Bacteria
08:34

MS2-Affinity Purification Coupled with RNA Sequencing in Gram-Positive Bacteria

Published on: February 23, 2021

7.7K

Degradation of SsrA-tagged proteins in streptococci

Liang Tao1, Indranil Biswas2

  • 1Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA.

Microbiology (Reading, England)
|February 4, 2015
PubMed

Insights

In Streptococcus mutans, tmRNA-tagged protein degradation involves ClpXP, ClpCP, and ClpEP proteases. Heat stress induces ClpCP and ClpEP activity, suggesting conserved roles in other streptococci.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Proteolysis

Background:

  • Prokaryotic tmRNA (transfer-messenger RNA) rescues stalled ribosomes by tagging truncated proteins with SsrA (small, stable RNA A).
  • SsrA-tagged proteins are targeted for degradation by proteases, primarily ClpXP and ClpAP in E. coli, and ClpXP in B. subtilis.
  • The proteases involved in SsrA-tagged protein degradation in streptococci are not fully characterized, though ClpXP is known to be major.

Purpose of the Study:

  • To investigate the proteases responsible for SsrA-tagged protein degradation in Streptococcus mutans.
  • To determine if heat stress influences the degradation pathways of SsrA-tagged proteins.
  • To predict the broader role of identified proteases in other streptococcal species.

Main Methods:

  • Protease activity assays using SsrA-tagged protein substrates.
  • Analysis of protein degradation in Streptococcus mutans under various conditions, including heat stress.
  • Bioinformatic analysis of conserved protease genes in streptococci.

Main Results:

  • In Streptococcus mutans, ClpXP, ClpCP, and ClpEP proteases all contribute to the degradation of SsrA-tagged proteins.
  • Proteolysis mediated by ClpCP and ClpEP is significantly induced by heat stress.
  • ClpCP and ClpEP proteins are highly conserved across streptococcal species.

Conclusions:

  • The degradation of SsrA-tagged proteins in Streptococcus mutans is a multi-protease process involving ClpXP, ClpCP, and ClpEP.
  • Heat stress enhances the activity of ClpCP and ClpEP in degrading SsrA-tagged proteins.
  • The involvement of ClpCP and ClpEP in SsrA-tagged protein degradation is likely conserved in other streptococci.

More Related Videos

Reporter-based Growth Assay for Systematic Analysis of Protein Degradation07:47

Reporter-based Growth Assay for Systematic Analysis of Protein Degradation

Published on: November 6, 2014

11.2K
Growth-based Determination and Biochemical Confirmation of Genetic Requirements for Protein Degradation in Saccharomyces cerevisiae10:57

Growth-based Determination and Biochemical Confirmation of Genetic Requirements for Protein Degradation in Saccharomyces cerevisiae

Published on: February 16, 2015

10.3K

Related Concept Videos

Staphylococcal Skin Infections01:29

Staphylococcal Skin Infections

Staphylococcus aureus is a Gram-positive coccus that resides harmlessly on the skin and mucous membranes of healthy individuals. When the skin barrier is breached, it can shift from a commensal to an opportunistic pathogen. This transition is facilitated by surface adhesins, such as clumping factor B and S. aureus surface protein G (SasG), which bind to structural proteins, including loricrin and cytokeratin, in the damaged epidermis. Protein A, another key factor, binds the Fc region of...
102
Export of Misfolded Proteins out of the ER01:32

Export of Misfolded Proteins out of the ER

After folding, the ER assesses the quality of secretory and membrane proteins. The correctly folded proteins are cleared by the calnexin cycle for transport to their final destination, while misfolded proteins are held back in the ER lumen. The ER chaperones attempt to unfold and refold the misfolded proteins but sometimes fail to achieve the correct native conformation. Such terminally misfolded proteins are then exported to the cytosol by ER-associated degradation or ERAD pathway for...
5.7K
Tagging and Fusion Proteins01:24

Tagging and Fusion Proteins

Proteins are involved in several cellular processes and biochemical reactions. Analyzing a specific protein of interest requires it to be isolated from the other proteins in the cell. This is achieved by overexpressing the specific gene in a suitable host to produce large quantities of the target protein. A tag or label is recombined with the gene to produce a fusion protein containing the target protein and the tag. The tags on these fusion proteins can then be used for easy detection and...
9.0K