GO:0016846 carbon-sulfur lyase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0016846 carbon-sulfur lyase activity describes enzymes that catalyze the elimination of hydrogen sulfide or substituted H2S from carbon-sulfur substrates.
• These enzymes are best known for releasing volatile thiols that shape the aroma of wine, beer, and Baijiu through carbon-sulfur lyase activity.
• In Saccharomyces cerevisiae, the IRC7 gene encodes a carbon-sulfur beta-lyase whose inactivating mutations are common in wine yeasts and reduce volatile sulfur compound production.
• Carbon-sulfur lyases also participate in cysteine S-conjugate metabolism, a pathway relevant to xenobiotic detoxification and prodrug activation.
• The term is a molecular_function in the Gene Ontology, defined by catalytic elimination chemistry rather than by a single protein family or pathway.
• Researchers study carbon-sulfur lyase activity using biochemical assays, heterologous expression, gene knockout, and volatile compound profiling.
Description
GO:0016846 carbon-sulfur lyase activity is a Gene Ontology molecular_function term defined as the catalysis of the elimination of hydrogen sulfide or substituted H2S. This activity is chemically distinct from simple hydrolysis because it removes a sulfur-containing leaving group from a carbon-sulfur bond, often generating a reactive thiol or an unsaturated product. The term is therefore used to annotate enzymes that act on substrates such as cysteine S-conjugates, methionine derivatives, and dimethylsulfoniopropionate (DMSP). Because the products of these reactions are often volatile sulfur compounds, carbon-sulfur lyase activity has become a central concept in food and flavor microbiology as well as in drug metabolism. In wine and beer fermentations, yeast carbon-sulfur lyases release thiols that contribute desirable tropical and fruity aromas. In oral anaerobes such as Fusobacterium nucleatum, a carbon-sulfur lyase produces flavor sulfur compounds from cysteine conjugates. In mammalian systems, cysteine S-conjugate beta-lyases are studied for their roles in xenobiotic metabolism and prodrug bioactivation. For researchers, GO:0016846 provides a precise functional label that links sequence, biochemical assay, and physiological outcome across these diverse contexts.
carbon-sulfur lyase activity At A Glance
| GO ID | GO:0016846 |
|---|---|
| GO term | carbon-sulfur lyase activity |
| Ontology | molecular_function |
| Synonym | carbon-sulphur lyase activity |
| Definition | Catalysis of the elimination of hydrogen sulfide or substituted H2S. |
| Major function | Elimination of hydrogen sulfide or substituted H2S from carbon-sulfur substrates, often releasing volatile thiols. |
| Representative substrates | Cysteine S-conjugates, DMSP, and related sulfur-containing compounds. |
| Representative enzymes | Yeast Irc7p, DMSP lyases, and bacterial carbon-sulfur lyases. |
| Common research areas | Wine, beer, and Baijiu flavor; xenobiotic metabolism; microbial sulfur cycling. |
What Is GO:0016846?
In plain terms, GO:0016846 carbon-sulfur lyase activity means an enzyme that breaks a carbon-sulfur bond by eliminating hydrogen sulfide or a substituted H2S molecule, rather than by adding water or transferring a group. The official QuickGO definition is Catalysis of the elimination of hydrogen sulfide or substituted H2S. The synonym carbon-sulphur lyase activity reflects the same chemistry. This activity is classified as a molecular_function, so it describes what the protein does at the catalytic level, not where it acts or which pathway it belongs to. Enzymes annotated with this term often use pyridoxal phosphate or other cofactors, and they can act on cysteine S-conjugates, DMSP, or related sulfur-containing substrates. The reaction typically produces a thiol, a volatile sulfur compound, or an unsaturated carbon skeleton, which is why the term is frequently encountered in studies of flavor formation and sulfur metabolism.
Why Is carbon-sulfur lyase activity Important in Cell Biology?
GO:0016846 carbon-sulfur lyase activity matters because it connects a precise catalytic chemistry to diverse biological and industrial outcomes. In food and beverage fermentations, these enzymes determine the release of volatile thiols that define the sensory profile of wine, beer, and Baijiu. In microbiology, they contribute to sulfur cycling and to the metabolism of cysteine conjugates. In pharmacology and toxicology, cysteine S-conjugate beta-lyases are studied for their roles in xenobiotic detoxification and prodrug activation. Because the same GO term can annotate enzymes from yeast, bacteria, and mammals, it provides a shared vocabulary for comparing mechanism across species. For gene editing researchers, this term helps prioritize candidate genes whose knockout or point mutation may alter thiol production or sulfur metabolism.
• Defines a specific catalytic chemistry: elimination of hydrogen sulfide or substituted H2S from carbon-sulfur substrates.
• Explains the biogenesis of volatile thiols that shape wine, beer, and Baijiu aroma.
• Links yeast genetics to flavor: IRC7 mutations attenuate carbon-sulfur beta-lyase activity in wine yeasts.
• Supports studies of cysteine S-conjugate metabolism and xenobiotic detoxification.
• Provides a functional annotation for DMSP lyases and related microbial sulfur enzymes.
• Enables cross-species comparison of carbon-sulfur lyase enzymes across microbial diversity.
• Guides metabolic engineering of thiol release in fermented beverages.
• Helps interpret oral microbiome sulfur metabolism in anaerobes such as Fusobacterium nucleatum.
• Informs prodrug design where cysteine S-conjugate beta-lyases activate sulfur-containing prodrugs.
• Offers a testable hypothesis for CRISPR knockout or point-mutation studies of candidate lyase genes.
What Happens During carbon-sulfur lyase activity?
Substrate recognition and binding
In simple terms: The enzyme first grabs a sulfur-containing molecule and positions it for reaction.
Carbon-sulfur lyases bind substrates that contain a carbon-sulfur bond, such as cysteine S-conjugates or DMSP. The binding step orients the sulfur-containing leaving group toward the catalytic center so that elimination can occur. In yeast, the Irc7p enzyme acts on sulfur-containing precursors to release volatile thiols, and its activity depends on the substrate being correctly positioned. Biochemical profiling of DMSP lyases has shown that substrate specificity varies among enzymes annotated with carbon-sulfur lyase activity.
Catalytic elimination of hydrogen sulfide or substituted H2S
In simple terms: The enzyme cuts the carbon-sulfur bond and releases a sulfur-containing leaving group.
The defining step of GO:0016846 is the elimination of hydrogen sulfide or substituted H2S from the substrate. This reaction often requires a cofactor such as pyridoxal phosphate in cysteine S-conjugate beta-lyases, which facilitates bond cleavage. The elimination produces a thiol or a related sulfur-containing product, and in many cases the remaining carbon skeleton becomes unsaturated. In food fermentations, this step is responsible for releasing volatile thiols that contribute to aroma.
Product release and volatile thiol formation
In simple terms: After the reaction, the newly formed sulfur compound is released and can be detected as an aroma or metabolite.
Following catalysis, the enzyme releases the sulfur-containing product, which may be a volatile thiol such as 2-furfurylthiol or a related compound. In Baijiu yeast, carbon-sulfur lyase activity from Saccharomyces cerevisiae G20 generates 2-furfurylthiol, a key aroma compound. In wine yeasts, the release of volatile sulfur compounds is attenuated when IRC7 is inactivated, demonstrating that product formation depends on this activity. The released thiols can then be measured by gas chromatography or related analytical methods.
Physiological and ecological context
In simple terms: The reaction matters not only in the test tube but also in the environment where the microbe lives.
Carbon-sulfur lyase activity contributes to sulfur metabolism in diverse microbial niches, including fermented beverages and the oral cavity. In Fusobacterium nucleatum, a carbon-sulfur lyase from the oral anaerobe produces flavor sulfur compounds from cysteine conjugates, linking the activity to oral microbial ecology. In wine and beer, the activity influences the final aroma profile and therefore the quality of the product. Exploring carbon-sulfur lyases across microbial diversity has been proposed as a way to enhance thiol release in beer and wine.
Key Genes Involved in GO:0016846 carbon-sulfur lyase activity
The following genes and proteins are representative of carbon-sulfur lyase activity and its study across yeast, bacteria, and mammalian systems.
| Gene | Major Role | Research Relevance |
|---|---|---|
| IRC7 | Encodes a carbon-sulfur beta-lyase in Saccharomyces cerevisiae that releases volatile thiols. | Inactivating mutations are common in wine yeasts and attenuate volatile sulfur compound production. |
| IRC7 (Saccharomyces cerevisiae G20) | Carbon-sulfur lyase that generates 2-furfurylthiol in Baijiu fermentation. | Provides a model for studying thiol generation in distilled spirits. |
| DMSP lyase genes | Encode enzymes that cleave dimethylsulfoniopropionate, a representative carbon-sulfur lyase substrate. | Used for biochemical profiling of DMSP lyases and their substrate specificity. |
| Fusobacterium nucleatum carbon-sulfur lyase | Produces flavor sulfur compounds from cysteine conjugates in the oral anaerobe. | Links carbon-sulfur lyase activity to oral microbial metabolism and flavor formation. |
| Cysteine S-conjugate beta-lyase genes | Encode enzymes that metabolize cysteine S-conjugates and can activate prodrugs. | Central to xenobiotic detoxification and prodrug bioactivation studies. |
| Methioninase (L-methionine gamma-lyase) | Catalyzes a carbon-sulfur lyase-type reaction on methionine. | Studied in methioninase gene therapy for methionine-dependent tumors. |
| Mitochondrial ferredoxin-2 (FDX2) | Participates in iron-sulfur cluster assembly, a process related to sulfur handling. | Provides context for sulfur-related mitochondrial biology, though not a carbon-sulfur lyase itself. |
| Microbial carbon-sulfur lyases from diverse taxa | Release thiols in beer and wine fermentations. | Targets for bioprospecting and enzyme engineering. |
| Yeast sulfur metabolism genes | Support precursor supply for carbon-sulfur lyase reactions. | Modulate the availability of substrates for thiol release. |
| Bacterial cysteine conjugate lyases | Metabolize cysteine S-conjugates in bacteria. | Relevant to oral and gut microbial sulfur metabolism. |
| Plant DMSP-related lyases | Contribute to sulfur cycling in marine and terrestrial environments. | Used in biochemical profiling studies of DMSP lyases. |
| Fungal carbon-sulfur lyases | Contribute to aroma formation in fermented foods. | Candidates for strain improvement in food biotechnology. |
| Mammalian cysteine S-conjugate beta-lyases | Detoxify cysteine S-conjugates and bioactivate prodrugs. | Studied for drug metabolism and toxicity. |
| Methioninase variants | Engineered enzymes with carbon-sulfur lyase activity on methionine. | Used in gene therapy models of methionine dependence. |
| Iron-sulfur cluster assembly proteins | Support sulfur trafficking in mitochondria. | Provide mechanistic context for sulfur-related enzyme maturation. |
How Is carbon-sulfur lyase activity Regulated?
Carbon-sulfur lyase activity is regulated at multiple levels. In wine yeasts, inactivating mutations in IRC7 are common and directly attenuate carbon-sulfur beta-lyase activity, showing that genetic variation controls the activity. Substrate availability also regulates the flux through this activity, because the enzymes require sulfur-containing precursors such as cysteine conjugates or DMSP. In food fermentation contexts, the expression of carbon-sulfur lyase genes and the supply of precursors determine the amount of volatile thiol released. In mammalian systems, cysteine S-conjugate beta-lyase activity can be influenced by cofactor availability and by the presence of competing metabolic pathways. Methioninase, which catalyzes a related carbon-sulfur lyase reaction, is studied in gene therapy settings where its expression is deliberately controlled. Overall, regulation occurs through a combination of genetic variation, substrate supply, and cofactor availability rather than through a single dedicated regulatory circuit.
carbon-sulfur lyase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| Methioninase | Methionine-dependent tumors; gene therapy | Knockout or overexpression in cancer cell lines |
| Cysteine S-conjugate beta-lyase | Xenobiotic detoxification and prodrug activation | Point-mutation models to alter catalytic activity |
| IRC7 | Wine yeast volatile sulfur compound production | Knockout and knock-in in Saccharomyces cerevisiae |
| Fusobacterium nucleatum carbon-sulfur lyase | Oral microbial sulfur metabolism | Bacterial knockout and heterologous expression |
| DMSP lyase | Microbial sulfur cycling | Biochemical profiling with purified enzymes |
Carbon-sulfur lyases and prodrug activation in cancer therapy
Cysteine S-conjugate beta-lyases can bioactivate sulfur-containing prodrugs, and this property has been explored in the context of cancer chemotherapy. Methioninase, which catalyzes a carbon-sulfur lyase-type reaction on methionine, has been studied in methioninase gene therapy for methionine-dependent tumors. These examples show that carbon-sulfur lyase activity can be harnessed to convert inactive compounds into active drugs or to deplete specific amino acids in tumor cells.
Sulfur metabolism and xenobiotic detoxification
Cysteine S-conjugate beta-lyases are involved in the metabolism of cysteine S-conjugates, a pathway relevant to xenobiotic detoxification. Dysregulation of this pathway can influence the toxicity of sulfur-containing compounds. Because the same GO term annotates enzymes from different species, comparative studies can help identify conserved and divergent features of sulfur metabolism.
Oral microbial sulfur metabolism
A carbon-sulfur lyase from the oral anaerobe Fusobacterium nucleatum produces flavor sulfur compounds from cysteine conjugates. This links carbon-sulfur lyase activity to oral microbial ecology and to the production of volatile sulfur compounds in the oral cavity. Understanding this activity may inform studies of oral malodor and microbial sulfur metabolism.
From carbon-sulfur lyase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of IRC7 reduce volatile thiol production? | IRC7 knockout in wine yeast |
| Can a point mutation alter substrate specificity of a carbon-sulfur lyase? | Point-mutation knock-in in the endogenous gene |
| Can a carbon-sulfur lyase gene from a new microbe enhance thiol release? | Heterologous overexpression in Saccharomyces cerevisiae |
| Does a cysteine S-conjugate beta-lyase activate a prodrug? | Knockout and overexpression in mammalian cell lines |
| Can methioninase gene therapy deplete methionine in tumors? | Methioninase overexpression in cancer models |
| What is the biochemical profile of a DMSP lyase? | Purified enzyme assays with substrate panels |
How to Study the carbon-sulfur lyase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Enzyme activity assay | Catalytic elimination of hydrogen sulfide or substituted H2S | Characterizing purified carbon-sulfur lyases |
| Gas chromatography | Volatile thiol products | Quantifying aroma compounds in fermented beverages |
| Heterologous expression | Functional activity of a candidate gene in a new host | Testing microbial carbon-sulfur lyases |
| Gene knockout | Loss-of-function effect on thiol production | Validating IRC7 function in wine yeast |
| Point mutation | Effect of specific amino acid changes on activity | Mapping catalytic residues |
| Comparative genomics | Distribution and diversity of carbon-sulfur lyases | Bioprospecting for new enzymes |
| Biochemical profiling | Substrate specificity of DMSP lyases | Classifying lyase family members |
| Prodrug activation assay | Conversion of a prodrug by cysteine S-conjugate beta-lyase | Drug metabolism studies |
Biochemical enzyme assays
Biochemical profiling of DMSP lyases provides a direct way to measure carbon-sulfur lyase activity using purified enzymes and defined substrates. These assays can determine substrate specificity, kinetic parameters, and cofactor requirements. Similar approaches have been used to characterize cysteine S-conjugate beta-lyases.
Volatile compound analysis
Gas chromatography and related analytical methods are used to detect volatile thiols released by carbon-sulfur lyase activity in wine, beer, and Baijiu. These methods link enzyme activity to sensory outcomes and can quantify the effect of gene knockouts or mutations.
Genetic and heterologous expression studies
Heterologous expression of candidate carbon-sulfur lyase genes in Saccharomyces cerevisiae allows researchers to test their contribution to thiol release. Knockout and mutation studies in the native host, such as IRC7 in wine yeast, provide complementary evidence. These approaches are essential for assigning function to genes annotated with GO:0016846.
Comparative and bioinformatic analysis
Exploring carbon-sulfur lyases across microbial diversity relies on sequence comparison and functional annotation to identify new enzymes with this activity. Bioinformatics can prioritize candidate genes for biochemical testing and for CRISPR-based editing.
How CRISPR Can Be Used to Study GO:0016846 carbon-sulfur lyase activity
Knockout
CRISPR knockout of a candidate carbon-sulfur lyase gene, such as IRC7 in wine yeast, can directly test whether the gene is required for volatile thiol production. Loss-of-function mutants show attenuated carbon-sulfur beta-lyase activity and reduced volatile sulfur compound production. This approach is a standard first step for assigning function to genes annotated with GO:0016846.
Point Mutation
CRISPR point mutation can be used to alter specific amino acids in a carbon-sulfur lyase to test their role in catalysis or substrate binding. For example, mutations that inactivate IRC7 are common in wine yeasts and provide natural evidence for the importance of specific residues. Similar strategies can be applied to cysteine S-conjugate beta-lyases to dissect their catalytic mechanism.
Knock-in
Knock-in of a carbon-sulfur lyase gene from a different microbe into a well-characterized host such as Saccharomyces cerevisiae allows functional testing of new enzymes. This approach has been proposed for exploring carbon-sulfur lyases across microbial diversity to enhance thiol release in beer and wine. Knock-in can also be used to tag the endogenous enzyme for localization or purification studies.
Overexpression
Overexpression of a carbon-sulfur lyase gene can increase the production of volatile thiols and help determine whether the enzyme is rate-limiting. In Baijiu yeast, carbon-sulfur lyase activity from Saccharomyces cerevisiae G20 generates 2-furfurylthiol, and overexpression could enhance this trait. Overexpression is also used in methioninase gene therapy studies to deplete methionine in tumor cells.
How EDITGENE Supports carbon-sulfur lyase activity Research
Researchers studying carbon-sulfur lyase activity-related genes often need to determine whether a candidate gene is causally involved in thiol release, sulfur metabolism, or prodrug activation. EDITGENE provides CRISPR-based cell models and screening services that allow precise knockout, point mutation, knock-in, and overexpression of genes annotated with GO:0016846, enabling functional validation in relevant yeast, bacterial, or mammalian systems.
Contact EDITGENE today to design your custom CRISPR model for carbon-sulfur lyase activity research.
Frequently Asked Questions About carbon-sulfur lyase activity
What is carbon-sulfur lyase activity?
Carbon-sulfur lyase activity (GO:0016846) is the catalysis of the elimination of hydrogen sulfide or substituted H2S from a carbon-sulfur substrate.
What genes are involved in carbon-sulfur lyase activity?
Representative genes include IRC7 in Saccharomyces cerevisiae, DMSP lyase genes, cysteine S-conjugate beta-lyase genes, and methioninase.
What is the GO ID for carbon-sulfur lyase activity?
The GO ID is GO:0016846, a molecular_function term in the Gene Ontology.
How is carbon-sulfur lyase activity measured?
It is measured by enzyme activity assays, volatile compound analysis, and heterologous expression studies.
Why is carbon-sulfur lyase activity important in wine and beer?
It releases volatile thiols that contribute to the aroma of wine and beer, and IRC7 mutations can attenuate this activity.
What is the role of IRC7 in carbon-sulfur lyase activity?
IRC7 encodes a carbon-sulfur beta-lyase in wine yeast, and inactivating mutations reduce volatile sulfur compound production.
Can CRISPR be used to study carbon-sulfur lyase activity?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression can be used to test the function of carbon-sulfur lyase genes.
What substrates do carbon-sulfur lyases act on?
They act on cysteine S-conjugates, DMSP, and related sulfur-containing compounds.
Is carbon-sulfur lyase activity involved in human disease?
Cysteine S-conjugate beta-lyases are studied in xenobiotic detoxification and prodrug activation, and methioninase is studied in cancer gene therapy.
What is the synonym for GO:0016846?
The synonym is carbon-sulphur lyase activity.
Conclusion
GO:0016846 carbon-sulfur lyase activity defines a specific and widely relevant catalytic function: the elimination of hydrogen sulfide or substituted H2S from carbon-sulfur substrates. This activity underlies the formation of volatile thiols in wine, beer, and Baijiu, contributes to microbial sulfur metabolism, and is studied in xenobiotic detoxification and prodrug activation. Because the term is a molecular_function, it provides a shared annotation that can be applied across yeast, bacteria, and mammalian enzymes. For researchers, precise CRISPR models of genes such as IRC7 and cysteine S-conjugate beta-lyases offer a direct route to test how this activity shapes flavor, metabolism, and therapeutic outcomes.
References
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- 2. Cordente AG et al.. 2019. Inactivating Mutations in Irc7p Are Common in Wine Yeasts, Attenuating Carbon-Sulfur β-Lyase Activity and Volatile Sulfur Compound Production.. Appl Environ Microbiol 85(6) PMID: 30658969
- 3. Lei L et al.. 2018. Biochemical Profiling of DMSP Lyases.. Methods Enzymol 605:269-289 PMID: 29909827
- 4. Neiers F et al.. 2022. Metabolism of Cysteine Conjugates and Production of Flavor Sulfur Compounds by a Carbon-Sulfur Lyase from the Oral Anaerobe Fusobacterium nucleatum.. J Agric Food Chem 70(32):9969-9979 PMID: 35920882
- 5. Steinhilper R et al.. 2024. Two-stage binding of mitochondrial ferredoxin-2 to the core iron-sulfur cluster assembly complex.. Nat Commun 15(1):10559 PMID: 39632806
- 6. Hoffman RM et al.. 2019. Methioninase Gene Therapy.. Methods Mol Biol 1866:173-197 PMID: 30725416
- 7. Zha M et al.. 2018. Generation of 2-Furfurylthiol by Carbon-Sulfur Lyase from the Baijiu Yeast Saccharomyces cerevisiae G20.. J Agric Food Chem 66(9):2114-2120 PMID: 29436228
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