Related Experiment Video
Updated: Jul 11, 2025
11:25
Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins
Published on: October 4, 2017
6.7K
Micrococcin cysteine-to-thiazole conversion through transient interactions between a scaffolding protein and two
Diana G Calvopina-Chavez1, Devan M Bursey1, Yi-Jie Tseng2
1Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602.
Biorxiv : the Preprint Server for Biology
|November 14, 2023
Summary
This study reveals how the antimicrobial micrococcin is made. A scaffold protein (TclI) dynamically interacts with two enzymes, ensuring precise modification of the micrococcin precursor peptide (TclE).
Area of Science:
- Biochemistry
- Molecular Biology
- Microbiology
Background:
- Ribosomally synthesized and post-translationally modified peptides (RiPPs) are crucial for microbial competition.
- Azole/azoline heterocycle formation is a key modification in RiPP biosynthesis, often involving scaffold proteins, cyclodehydratases, and dehydrogenases.
- Previous assumptions suggested a stable complex for these modifications, but the dynamic interactions were unclear.
Approach:
- Identified the minimal TclE leader region necessary for thiazole formation.
- Demonstrated complex formation between the scaffold protein (TclI) and the modifying enzymes (TclJ and TclN).
- Defined specific protein regions involved in complex formation and elucidated the mechanism of thiazole installation.
Key Points:
- The micrococcin precursor peptide (TclE) contains a core with six cysteine residues converted to thiazoles.
- The scaffold protein (TclI) is essential for presenting TclE to the cyclodehydratase (TclJ) and dehydrogenase (TclN).
- TclI interacts with TclJ and TclN in a mutually exclusive manner, creating a dynamic equilibrium for efficient modification.
Conclusions:
- The modification of TclE involves a dynamic interplay between TclI, TclJ, and TclN, rather than a stable enzyme complex.
- This dynamic mechanism ensures the complete and accurate installation of thiazole rings in the micrococcin precursor.
- Understanding this process provides insights into RiPP biosynthesis and microbial defense mechanisms.
More Related Videos
09:37Combining Non-reducing SDS-PAGE Analysis and Chemical Crosslinking to Detect Multimeric Complexes Stabilized by Disulfide Linkages in Mammalian Cells in Culture
Published on: May 2, 2019
10.2K
07:16Resin-Assisted Capture Coupled with Isobaric Tandem Mass Tag Labeling for Multiplexed Quantification of Protein Thiol Oxidation
Published on: June 21, 2021
1.8K
Related Concept Videos
01:57Protein Complexes with Interchangeable Parts
2.6K
Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order...
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order...
2.6K
01:26Protein Modifications in the RER
5.2K
Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal...
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal...
5.2K
02:41Protein Complex Assembly
10.6K
Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes.
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Many viruses self-assemble into a fully functional unit using the infected host cell to...
10.6K
01:19Translocation of Proteins into the Mitochondria
3.1K
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
3.1K
02:04Covalently Linked Protein Regulators
6.8K
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein....
These groups modify specific amino acids in a protein....
6.8K
01:32Export of Misfolded Proteins out of the ER
3.6K
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...
3.6K