Related Experiment Video
Updated: Mar 29, 2026
09:27
Functional Complementation Analysis FCA: A Laboratory Exercise Designed and Implemented to Supplement the Teaching of Biochemical Pathways
Published on: June 24, 2016
18.3K
Disulfide-Bond-Forming Pathways in Gram-Positive Bacteria
Melissa E Reardon-Robinson1, Hung Ton-That1
1Department of Microbiology & Molecular Genetics, University of Texas Health Science Center, Houston, Texas, USA merobinson1020@gmail.com ton-that.hung@uth.tmc.edu.
Journal of Bacteriology
|December 9, 2015
Summary
Disulfide bond formation in Gram-positive bacteria is crucial for protein stability. The membrane-bound oxidoreductase MdbA is essential for this process and represents a potential target for novel antibacterial drugs.
Area of Science:
- Microbiology
- Biochemistry
- Molecular Biology
Background:
- Disulfide bonds are vital for secreted protein stability and function.
- Thiol-disulfide oxidoreductases (Dsb) catalyze these bonds in Gram-negative bacteria's periplasm.
- Disulfide bond formation in Gram-positive bacteria, lacking periplasmic compartments, is less understood.
Purpose of the Study:
- To explore disulfide-bond-forming pathways in Gram-positive bacteria.
- To investigate the role of Dsb-like proteins in actinobacteria.
- To highlight MdbA as a potential antibacterial drug target.
Main Methods:
- Bioinformatic analyses to identify Dsb-like proteins in high-GC-content bacteria.
- Utilizing Actinomyces oris and Corynebacterium diphtheriae as model organisms.
- Characterizing the function of the membrane-bound oxidoreductase MdbA.
Main Results:
- Bioinformatics suggested reliance on disulfide-bond-forming pathways in actinobacteria.
- Dsb-like proteins were identified in Mycobacterium tuberculosis.
- MdbA was identified as the catalyst for disulfide bonds in Actinomyces oris and Corynebacterium diphtheriae.
Conclusions:
- MdbA is essential for disulfide bond formation in Gram-positive bacteria.
- MdbA plays a significant role in pathogenesis and growth.
- MdbA represents a promising target for developing new antibacterial therapies.
Related Concept Videos
01:20Sulfur Assimilation
490
Sulfur is an essential element in biological systems, contributing to synthesizing key biomolecules, including amino acids such as cysteine and methionine, and cofactors such as coenzyme A and biotin. Microorganisms primarily assimilate sulfur as sulfate (SO₄²⁻) from the environment, which must undergo a series of biochemical transformations before it can be incorporated into cellular components. As sulfate is highly oxidized, it must undergo assimilatory sulfate reduction to...
490
01:26Protein Modifications in the RER
7.5K
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...
7.5K
01:17Gram-negative Bacterial Protein Secretion Systems
1.4K
Gram-negative bacteria utilize sophisticated protein secretion systems to transport proteins across their double-membrane envelope into the extracellular environment or host cells. Based on their mechanism of action, these systems are classified into one-step and two-step pathways.One-Step Secretion Systems (Types I, III, IV, and VI)One-step secretion systems bypass the periplasm entirely, forming a continuous channel that spans both the inner and outer membranes:Type I Secretion System (T1SS):...
1.4K
02:26Preparation and Reactions of Sulfides
6.0K
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
6.0K
01:28Peptidoglycan Synthesis
4.1K
Structure of PeptidoglycanPeptidoglycan is a vital structural component of the bacterial cell wall, providing mechanical strength and shape to the cell. It consists of repeating units of two sugars—N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)—linked by β-1,4 glycosidic bonds. These sugar chains are cross-linked by short peptide chains, forming a mesh-like polymer that surrounds the bacterial plasma membrane.Cytoplasmic Phase – Precursor SynthesisPeptidoglycan...
4.1K
01:17Gene Regulation During Sporulation
638
Sporulation is a complex developmental process that allows certain Gram-positive bacteria, such as Bacillus subtilis and Clostridium species, to survive extreme environmental conditions. This process is tightly regulated by a series of signaling cascades and transcriptional controls, ensuring the formation of a highly resistant endospore.Sporulation is triggered by unfavorable conditions, such as nutrient depletion, and is governed by a phosphorelay system. One of the sensor kinases, such as...
638