GO:0004043 L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0004043 describes the enzymatic activity that converts (S)-2-amino-6-oxohexanoate to L-2-aminoadipate using NAD(P)+ as a cofactor, a key step in the alpha-aminoadipate pathway for lysine biosynthesis.
• The enzyme is widely known as alpha-aminoadipate reductase (AAR) and is encoded by LYS2 in fungi such as Saccharomyces cerevisiae, Candida albicans, Schizosaccharomyces pombe, and Penicillium chrysogenum.
• AAR requires posttranslational activation by a phosphopantetheinyl transferase (Lys5p/Lys7p in yeast, or the human ortholog) to become catalytically active.
• In Penicillium chrysogenum, AAR activity is regulated by nitrogen sources and lysine, linking it to penicillin biosynthesis.
• Mutations in the human ortholog of LYS5 cause a rare neurometabolic disorder, highlighting the biomedical relevance of this activity.
• Studying GO:0004043 helps researchers understand fungal lysine biosynthesis, antibiotic production, and potential antifungal drug targets.
Description
L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity (GO:0004043) is a molecular function that catalyzes the NAD(P)+-dependent oxidation of (S)-2-amino-6-oxohexanoate to L-2-aminoadipate. This reaction is a central step in the alpha-aminoadipate pathway, the fungal route for lysine biosynthesis, and is carried out by the enzyme alpha-aminoadipate reductase (AAR). Because lysine is essential for protein synthesis, this activity is critical for fungal growth and survival. In addition to its role in primary metabolism, AAR activity is also linked to secondary metabolism, such as penicillin production in Penicillium chrysogenum. Understanding GO:0004043 is therefore important for both fundamental enzymology and applied microbiology, including the development of antifungal strategies.
L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity At A Glance
| GO ID | GO:0004043 |
|---|---|
| GO term | L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity |
| Ontology | molecular_function |
| Synonym | alpha-aminoadipate reductase activity; AAR; 2-aminoadipate semialdehyde dehydrogenase activity |
| Major function | Catalyzes the NAD(P)+-dependent oxidation of (S)-2-amino-6-oxohexanoate to L-2-aminoadipate in lysine biosynthesis |
| Cofactor | NAD+ or NADP+ |
| Pathway | Alpha-aminoadipate pathway for lysine biosynthesis |
| Representative genes | LYS2 (Saccharomyces cerevisiae, Candida albicans, Schizosaccharomyces pombe, Penicillium chrysogenum) |
| Activation | Requires posttranslational phosphopantetheinylation by a PPTase (Lys5p/Lys7p) |
What Is GO:0004043?
According to the Gene Ontology, GO:0004043 is defined as the catalysis of the reaction: (S)-2-amino-6-oxohexanoate + NAD(P)+ + H2O = L-2-aminoadipate + NAD(P)H + 2 H+. In simpler terms, it is an oxidoreductase activity that uses NAD+ or NADP+ to convert an aminoadipate semialdehyde derivative into L-2-aminoadipate, a precursor in the alpha-aminoadipate lysine biosynthesis pathway.
Why Is L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity Important in Cell Biology?
GO:0004043 is essential for the alpha-aminoadipate pathway, which is the sole route for lysine biosynthesis in many fungi and some bacteria. Because lysine is a building block for proteins, inhibition of this activity can block fungal growth, making it a potential target for antifungal drugs. Moreover, in Penicillium chrysogenum, the flux through this step influences penicillin production, connecting primary and secondary metabolism. In humans, the orthologous enzyme is involved in a neurometabolic disorder, underscoring its broader biomedical significance.
• Provides a key step in fungal lysine biosynthesis, essential for protein synthesis and cell growth.
• Represents a validated target for antifungal drug discovery due to its absence in humans.
• Regulates carbon flux into penicillin biosynthesis in Penicillium chrysogenum.
• Requires posttranslational activation, offering a model for studying enzyme regulation.
• Mutations in the human ortholog of LYS5 cause a rare inherited disorder.
• Serves as a paradigm for understanding alpha-aminoadipate pathway enzymology.
• Enables metabolic engineering of lysine production in industrial fungi.
• Facilitates phylogenetic studies of lysine biosynthesis across species.
• Provides a tool for screening antifungal compounds targeting AAR.
• Links primary metabolism to secondary metabolite production.
Molecular Mechanism of L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity
Substrate Recognition and Binding
In simple terms: The enzyme grabs its substrate, (S)-2-amino-6-oxohexanoate, and holds it in place.
Alpha-aminoadipate reductase (AAR) specifically binds (S)-2-amino-6-oxohexanoate, the substrate for the reaction. The enzyme's active site accommodates this molecule and positions it for catalysis, as demonstrated by biochemical studies of the purified enzyme from Saccharomyces cerevisiae and Penicillium chrysogenum.
Catalytic Mechanism and Cofactor Use
In simple terms: The enzyme uses NAD+ or NADP+ to remove electrons from the substrate, turning it into L-2-aminoadipate.
The reaction catalyzed by GO:0004043 involves the oxidation of (S)-2-amino-6-oxohexanoate to L-2-aminoadipate, with concomitant reduction of NAD(P)+ to NAD(P)H. This oxidoreductase activity is dependent on the presence of NAD+ or NADP+ as an electron acceptor. Site-directed mutagenesis studies have identified conserved amino acid residues in the catalytic domains of AAR that are critical for this activity.
Posttranslational Activation by Phosphopantetheinylation
In simple terms: The enzyme needs a chemical tag added by another protein to become active.
AAR is activated by posttranslational modification, specifically phosphopantetheinylation, which is catalyzed by a phosphopantetheinyl transferase (PPTase) encoded by LYS5 in Saccharomyces cerevisiae or its orthologs. In Candida albicans and Schizosaccharomyces pombe, the PPTase Lys7p activates AAR (Lys1p) by transferring a phosphopantetheinyl group from coenzyme A to a conserved serine residue in the activation domain. Mutational analysis has shown that this modification is essential for catalytic activity.
Regulation by Nitrogen and Lysine
In simple terms: The enzyme's production and activity can be turned up or down depending on the nitrogen source and lysine levels.
In Penicillium chrysogenum and Acremonium chrysogenum, the formation of alpha-aminoadipate reductase is regulated by the nitrogen source, and its activity is inhibited by lysine. This regulation links the enzyme to the flux of alpha-aminoadipate into penicillin biosynthesis, as demonstrated by studies showing that lysine inhibition affects penicillin production.
Role in the Alpha-Aminoadipate Pathway
In simple terms: This enzyme is one step in a chain of reactions that makes lysine.
GO:0004043 represents a key step in the alpha-aminoadipate pathway, which converts alpha-aminoadipate to lysine in fungi. The reaction product, L-2-aminoadipate, is further metabolized to lysine. In Saccharomyces cerevisiae, mutants lacking this activity (lys2 and lys5 mutants) are lysine auxotrophs, confirming its essential role in the pathway.
Key Genes Involved in GO:0004043 L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity
The following genes and proteins are directly associated with L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity (GO:0004043) across various organisms.
| Gene | Major Role | Research Relevance |
|---|---|---|
| LYS2 (Saccharomyces cerevisiae) | Encodes alpha-aminoadipate reductase (AAR), the enzyme catalyzing GO:0004043 | Model for studying lysine biosynthesis and enzyme regulation |
| LYS5 (Saccharomyces cerevisiae) | Encodes phosphopantetheinyl transferase that activates AAR | Essential for posttranslational activation; human ortholog linked to disease |
| LYS2 (Candida albicans) | Encodes AAR; site-directed mutational analysis of catalytic domains | Fungal pathogen model; potential antifungal target |
| LYS7 (Schizosaccharomyces pombe) | Encodes PPTase that activates AAR (Lys1p) | Study of posttranslational activation and phylogenetics |
| lys2 (Penicillium chrysogenum) | Encodes alpha-aminoadipate reductase; regulated by nitrogen and lysine | Industrial penicillin production; regulation of secondary metabolism |
| AAR (Acremonium chrysogenum) | Alpha-aminoadipate reductase activity; nitrate regulation | Comparative studies of lysine biosynthesis and antibiotic production |
| Lys1p (Schizosaccharomyces pombe) | Alpha-aminoadipate reductase (AAR) | Model for enzyme activation and catalysis |
| Lys2p (Candida albicans) | Alpha-aminoadipate reductase (AAR) | Site-directed mutagenesis of catalytic domains |
| Human LYS5 ortholog (AASDHPPT) | Phosphopantetheinyl transferase; activates AASDH | Mutations cause rare neurometabolic disorder |
| AASDH (human) | Alpha-aminoadipate semialdehyde dehydrogenase | Human ortholog; potential role in lysine metabolism |
| LYS2 (Kluyveromyces lactis) | Alpha-aminoadipate reductase | Comparative genomics of lysine biosynthesis |
| LYS2 (Yarrowia lipolytica) | Alpha-aminoadipate reductase | Biotechnological production of lysine |
| LYS2 (Aspergillus nidulans) | Alpha-aminoadipate reductase | Model for fungal secondary metabolism |
| LYS2 (Neurospora crassa) | Alpha-aminoadipate reductase | Classical genetics of lysine biosynthesis |
| LYS2 (Schizosaccharomyces pombe) | Alpha-aminoadipate reductase | Posttranslational activation studies |
| LYS5 (Candida albicans) | Phosphopantetheinyl transferase | Activation of AAR in pathogenic yeast |
| LYS5 (Schizosaccharomyces pombe) | Phosphopantetheinyl transferase (Lys7p) | Phylogenetic analysis of PPTases |
| LYS2 (Penicillium chrysogenum) | Alpha-aminoadipate reductase | Penicillin biosynthesis regulation |
How Is L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity Regulated?
The activity of L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] (GO:0004043) is regulated at multiple levels. In Penicillium chrysogenum and Acremonium chrysogenum, the formation of alpha-aminoadipate reductase is induced by nitrate and repressed by preferred nitrogen sources, and its enzymatic activity is inhibited by lysine. This nitrogen regulation and lysine feedback control directly influence the flux of alpha-aminoadipate into penicillin biosynthesis. Additionally, the enzyme requires posttranslational activation by a phosphopantetheinyl transferase (Lys5p/Lys7p), which is essential for catalytic function. Site-directed mutagenesis has identified conserved residues in the activation domain that are critical for this regulation.
L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| Human LYS5 ortholog (AASDHPPT) | Neurometabolic disorder due to phosphopantetheinyl transferase deficiency | Patient-derived fibroblasts or CRISPR knock-in of patient mutations in cell lines |
| Candida albicans LYS2 | Fungal pathogenicity; lysine auxotrophy | CRISPR knockout in C. albicans to test virulence in infection models |
| Penicillium chrysogenum lys2 | Penicillin production; nitrogen regulation | CRISPR knockout or point mutations to study penicillin yield |
| Saccharomyces cerevisiae LYS2 | Lysine biosynthesis; model for enzyme function | Yeast knockout and revertant strains for biochemical assays |
| Schizosaccharomyces pombe Lys1p | Posttranslational activation; phylogenetic studies | CRISPR knock-in of tagged alleles for activation studies |
Neurometabolic Disorder Linked to Human LYS5 Ortholog
Mutations in the human ortholog of the yeast LYS5 gene, which encodes the phosphopantetheinyl transferase that activates alpha-aminoadipate semialdehyde dehydrogenase, cause a rare neurometabolic disorder. This highlights the importance of GO:0004043-related activation in human health and disease.
Fungal Pathogenesis and Antifungal Targets
The alpha-aminoadipate pathway, including GO:0004043, is essential for lysine biosynthesis in fungi such as Candida albicans. Because this pathway is absent in humans, the enzyme represents a promising target for antifungal drug development. Inhibitors of AAR could potentially block fungal growth and virulence.
Secondary Metabolism and Antibiotic Production
In Penicillium chrysogenum, the flux through GO:0004043 affects penicillin biosynthesis, linking primary lysine metabolism to secondary metabolite production. Dysregulation of this step can alter antibiotic yields, which is relevant for industrial microbiology.
From L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of AAR activity abolish lysine biosynthesis? | CRISPR knockout of LYS2 in Saccharomyces cerevisiae or Candida albicans |
| Which residues are essential for catalytic activity? | Point mutations in LYS2 catalytic domains via CRISPR |
| How does phosphopantetheinylation regulate AAR? | Knock-in of tagged LYS5 or LYS7 for interaction studies |
| Can overexpression of AAR increase penicillin production? | Overexpression of lys2 in Penicillium chrysogenum |
| What is the effect of lysine feedback on AAR activity? | Point mutations in regulatory regions of lys2 |
| How does AAR contribute to fungal virulence? | CRISPR knockout in Candida albicans followed by infection assays |
How to Study the L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Spectrophotometric NAD(P)H assay | Enzymatic activity of AAR | Kinetic characterization of wild-type and mutant enzymes |
| Site-directed mutagenesis | Effect of specific amino acid substitutions | Identification of catalytic residues |
| CRISPR-Cas9 knockout | Loss-of-function phenotype | Testing essentiality of LYS2 in fungi |
| RNA-seq | Transcriptional changes | Regulation by nitrogen and lysine |
| Co-immunoprecipitation | Protein-protein interactions | AAR-PPTase complex formation |
| Mass spectrometry | Posttranslational modifications | Detection of phosphopantetheinylation |
| Growth assays | Lysine auxotrophy | Functional complementation of lys2 mutants |
| Penicillin production assay | Secondary metabolite yield | Linking AAR activity to antibiotic production |
Enzymatic Activity Assays
Direct measurement of L-aminoadipate-semialdehyde dehydrogenase activity can be performed using spectrophotometric assays that monitor NAD(P)H production at 340 nm. Such assays have been used to characterize the enzyme from Saccharomyces cerevisiae and Penicillium chrysogenum.
Site-Directed Mutagenesis and CRISPR Editing
Site-directed mutagenesis has been instrumental in identifying critical residues in the catalytic and activation domains of AAR. CRISPR-Cas9 can be used to introduce precise point mutations or knockouts in LYS2 or LYS5 genes to study their function in vivo.
Gene Expression Analysis
Quantitative RT-PCR and RNA-seq can measure the expression of LYS2 and LYS5 under different nitrogen sources or lysine concentrations, as demonstrated in Penicillium chrysogenum. This helps elucidate transcriptional regulation of the enzyme.
Protein Interaction and Posttranslational Modification Studies
Co-immunoprecipitation and mass spectrometry can detect the interaction between AAR and its PPTase, as well as the phosphopantetheinylation modification. These methods are key to understanding the activation mechanism.
How CRISPR Can Be Used to Study GO:0004043 L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity
Knockout
CRISPR-Cas9 knockout of LYS2 or LYS5 can create lysine auxotrophic strains, confirming the essential role of GO:0004043 in fungal lysine biosynthesis. Such knockouts are valuable for studying the pathway and for screening antifungal compounds.
Point Mutation
CRISPR-mediated point mutations can be introduced into conserved residues of LYS2 to dissect the catalytic mechanism and identify residues essential for substrate binding or cofactor interaction. This approach has been validated by site-directed mutagenesis studies.
Knock-in
Knock-in of epitope tags or fluorescent proteins at the endogenous LYS2 or LYS5 loci allows real-time monitoring of protein localization and interaction. This is useful for studying posttranslational activation and complex formation.
Overexpression
CRISPR activation (CRISPRa) or plasmid-based overexpression of LYS2 can increase AAR levels, which may enhance lysine or penicillin production in industrial fungi. Overexpression studies help determine rate-limiting steps in the pathway.
How EDITGENE Supports L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity Research
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Contact EDITGENE today to design your custom CRISPR model for L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity research.
Frequently Asked Questions About L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity
What is L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity?
It is an enzymatic activity (GO:0004043) that catalyzes the NAD(P)+-dependent oxidation of (S)-2-amino-6-oxohexanoate to L-2-aminoadipate, a step in fungal lysine biosynthesis.
What genes are involved in L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity?
The main genes are LYS2, encoding alpha-aminoadipate reductase, and LYS5, encoding the phosphopantetheinyl transferase that activates it.
Which organisms have this enzyme?
It is found in fungi such as Saccharomyces cerevisiae, Candida albicans, Schizosaccharomyces pombe, and Penicillium chrysogenum.
What is the role of LYS5 in this activity?
LYS5 encodes a phosphopantetheinyl transferase that posttranslationally activates AAR by adding a phosphopantetheinyl group.
How is this enzyme regulated?
It is regulated by nitrogen sources and lysine feedback inhibition, and requires posttranslational activation.
Is this enzyme a drug target?
Yes, because the alpha-aminoadipate pathway is absent in humans, AAR is a potential target for antifungal drugs.
What diseases are linked to this activity?
Mutations in the human LYS5 ortholog cause a rare neurometabolic disorder; fungal pathogens rely on this pathway for virulence.
How can I study this enzyme in the lab?
You can use enzymatic assays, CRISPR knockout, site-directed mutagenesis, and RNA-seq to study its function and regulation.
What is the alpha-aminoadipate pathway?
It is a fungal metabolic route for lysine biosynthesis in which GO:0004043 is a key step.
Does this enzyme exist in humans?
Humans have an orthologous enzyme, AASDH, and its activating PPTase; mutations in the PPTase cause a neurometabolic disorder.
Conclusion
L-aminoadipate-semialdehyde dehydrogenase [NAD(P)+] activity (GO:0004043) is a critical enzymatic step in fungal lysine biosynthesis and is tightly linked to secondary metabolism and pathogenesis. Its unique presence in fungi and absence in humans make it an attractive target for antifungal development. Continued research using CRISPR-based models will further elucidate its regulation and potential therapeutic applications.
References
- 1. Hijarrubia MJ et al.. 2002. Nitrate regulation of alpha-aminoadipate reductase formation and lysine inhibition of its activity in Penicillium chrysogenum and Acremonium chrysogenum.. Appl Microbiol Biotechnol 59(2-3):270-7 PMID: 12111157
- 2. Lu Y et al.. 1992. Regulation of alpha-aminoadipate reductase from Penicillium chrysogenum in relation to the flux from alpha-aminoadipate into penicillin biosynthesis.. Can J Microbiol 38(8):758-63 PMID: 1458368
- 3. Storts DR et al.. 1989. Properties of revertants of lys2 and lys5 mutants as well as alpha-aminoadipate-semialdehyde dehydrogenase from Saccharomyces cerevisiae.. Biochem Biophys Res Commun 161(1):182-6 PMID: 2499333
- 4. Praphanphoj V et al.. 2001. Identification of the alpha-aminoadipic semialdehyde dehydrogenase-phosphopantetheinyl transferase gene, the human ortholog of the yeast LYS5 gene.. Mol Genet Metab 72(4):336-42 PMID: 11286508
- 5. Guo S et al.. 2004. Posttranslational activation, site-directed mutation and phylogenetic analyses of the lysine biosynthesis enzymes alpha-aminoadipate reductase Lys1p (AAR) and the phosphopantetheinyl transferase Lys7p (PPTase) from Schizosaccharomyces pombe.. Yeast 21(15):1279-88 PMID: 15546125
- 6. Guo S et al.. 2001. Novel posttranslational activation of the LYS2-encoded alpha-aminoadipate reductase for biosynthesis of lysine and site-directed mutational analysis of conserved amino acid residues in the activation domain of Candida albicans.. J Bacteriol 183(24):7120-5 PMID: 11717270
- 7. Casqueiro J et al.. 1998. Characterization of the lys2 gene of Penicillium chrysogenum encoding alpha-aminoadipic acid reductase.. Mol Gen Genet 259(5):549-56 PMID: 9790587
- 8. Guo S et al.. 2003. Site-directed mutational analysis of the novel catalytic domains of alpha-aminoadipate reductase (Lys2p) from Candida albicans.. Mol Genet Genomics 269(2):271-9 PMID: 12756539
