Sulfite Reductase
Sulfite Reductase - Related Videos
02:15
Subculturing Sulfite-Reducing Anaerobic Bacteria from an Agar Culture
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2025
Source: Anwar, Z., et al. Enrichment and Detection of Clostridium perfringens Toxinotypes in Retail Food Samples. J. Vis. Exp. (2019).In this video, sulfite-reducing bacteria are cultured in a sulfite-containing agar medium, where they grow anaerobically and reduce sulfite to hydrogen sulfide, forming black precipitates with iron ions. Black colonies are isolated from the agar depth using aseptic techniques and transferred to fresh medium for continued anaerobic incubation.
12:34
DNA Methylation: Bisulphite Modification and Analysis
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Cited by 75 •
2011
The gold standard for DNA methylation analysis is genomic sequencing of bisulphite converted DNA. This method takes advantage of the increased sensitivity of cytosine compared with 5-methylcytosine (5-MeC) to bisulphite deamination under acidic conditions. Unmethylated cytosines can be distinguished from methylated cytosines after PCR amplification of the target genomic DNA.
13:18
Single Oocyte Bisulfite Mutagenesis
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Cited by 14 •
2012
Bisulfite mutagenesis is the gold standard for analyzing DNA methylation. Our modified protocol allows for DNA methylation analysis at the single-cell level and was specifically designed for individual oocytes. It can also be used for cleavage-stage embryos.
08:45
Isothermal Titration Calorimetry for Measuring Macromolecule-Ligand Affinity
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Cited by 84 •
2011
A general protocol for the use of isothermal titration calorimetry to monitor the binding thermodynamics for biological systems with moderate binding affinities is presented.
08:38
Targeted DNA Methylation Analysis by Next-generation Sequencing
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Cited by 83 •
2015
Bisulfite amplicon sequencing (BSAS) is a method for quantifying cytosine methylation in targeted genomic regions of interest. This method uses bisulfite conversion paired with PCR amplification of target regions prior to next-generation sequencing to produce absolute quantitation of DNA methylation at a base-specific level.
FAQs
The siroheme-containing center is the enzyme’s key catalytic component. It provides the chemical setting in which sulfite can undergo reduction to sulfide, linking the enzyme’s structure to its sulfur-transforming activity. This feature is especially important when comparing assimilatory and dissimilatory systems, because both rely on the same central sulfur conversion.
Ferredoxin or another electron donor supplies the reducing input needed for the sulfite-to-sulfide conversion. The donor therefore connects sulfite reductase to the cell’s broader electron-transfer network rather than acting as a passive accessory. The available donor can be relevant when distinguishing biosynthetic sulfur metabolism from energy-conserving sulfur metabolism.
Assimilatory and dissimilatory roles differ in biological purpose. In assimilatory metabolism, the product supports biosynthesis, including cysteine and sulfur-containing cofactors. In dissimilatory metabolism, anaerobic microorganisms use the transformation as part of sulfate respiration and generate sulfide. This distinction links the same sulfur chemistry to either cellular construction or energy conservation.
Because its reaction changes the chemical form of sulfur, sulfite reductase connects cellular metabolism with larger sulfur cycles. In plants, fungi, and bacteria, its activity can support incorporation of sulfur into biomolecules. In anaerobic microbial communities, sulfide generation also contributes to the environmental fate of sulfur compounds and nutrient cycling.
A useful comparison separates assimilatory systems from dissimilatory systems and identifies the electron source associated with each. The study can then relate sulfite reduction to its biological outcome: biosynthetic production of cysteine or sulfur-containing cofactors in one setting, versus sulfate respiration and sulfide generation in another.
In assimilatory contexts, sulfite reductase helps make reduced sulfur available for cellular biosynthesis. That sulfur can contribute to cysteine production and to sulfur-containing cofactors, giving the reaction significance beyond sulfite conversion alone. Examining these organisms therefore connects enzyme activity with the formation of essential sulfur-bearing cellular compounds.