GO:0102522 tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0102522 describes the radical SAM enzyme activity that installs the 3-amino-3-carboxypropyl group onto 4-demethylwyosine37 in tRNAPhe, producing wyosine derivatives.
• The reaction uses S-adenosyl-L-methionine (SAM) as the source of the aminocarboxypropyl group and releases 5'-S-methyl-5'-thioadenosine (MTA).
• In Archaea, the enzyme is often a bifunctional tRNAPhe:m1G/imG2 methyltransferase (Trm5a/Trm5b) that also methylates guanosine at position 37.
• Eukaryotic TYW1 is a radical SAM flavoenzyme, distinguishing it from the archaeal radical SAM enzymes that use pyruvate as a co-substrate.
• The wyosine modification is essential for translational fidelity and reading-frame maintenance in tRNAPhe.
• Dysregulation of tRNA modifications, including wyosine biosynthesis, is linked to mitochondrial dysfunction, neurological disorders, and cancer.
Description
GO:0102522, tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity, is a molecular function that catalyzes a key step in the biosynthesis of wyosine derivatives in tRNAPhe. This activity transfers the 3-amino-3-carboxypropyl group from S-adenosyl-L-methionine (SAM) to 4-demethylwyosine37, yielding 7-[(3S)-3-amino-3-carboxypropyl]-4-demethylwyosine37 and 5'-S-methyl-5'-thioadenosine (MTA). The enzyme responsible is a radical SAM protein, often called TYW1 in eukaryotes or Trm5a/Trm5b in Archaea, which contains iron-sulfur clusters essential for catalysis. Researchers study this activity because wyosine modifications are critical for tRNA stability, codon-anticodon interactions, and translational fidelity. Defects in tRNA modification pathways have been implicated in human diseases ranging from mitochondrial disorders to cancer.
tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity At A Glance
| GO ID | GO:0102522 |
|---|---|
| GO term | tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity |
| Ontology | molecular_function |
| Synonym | none |
| Major function | Catalyzes the transfer of the 3-amino-3-carboxypropyl group from SAM to 4-demethylwyosine37 in tRNAPhe, forming wyosine derivatives. |
| Cofactors | Radical SAM enzyme with [4Fe-4S] cluster; eukaryotic TYW1 also binds FAD. |
| Substrates | S-adenosyl-L-methionine and 4-demethylwyosine37 in tRNAPhe. |
| Products | 5'-S-methyl-5'-thioadenosine, H+, and 7-[(3S)-3-amino-3-carboxypropyl]-4-demethylwyosine37 in tRNAPhe. |
| Organisms | Archaea (e.g., Pyrococcus abyssi) and Eukarya (e.g., yeast, humans). |
What Is GO:0102522?
This GO term describes the catalytic activity of an enzyme that uses SAM to add an alpha-amino-alpha-carboxypropyl group to 4-demethylwyosine at position 37 of tRNAPhe. The reaction consumes SAM and 4-demethylwyosine37, producing MTA, a proton, and the modified tRNA base 7-[(3S)-3-amino-3-carboxypropyl]-4-demethylwyosine37. This is a radical SAM-dependent reaction, typically requiring a [4Fe-4S] cluster and, in some organisms, a flavin cofactor or pyruvate as an electron donor.
Why Is tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity Important in Cell Biology?
The wyosine modification at position 37 of tRNAPhe is crucial for maintaining the correct reading frame during translation and for efficient codon-anticodon pairing. The enzyme activity defined by GO:0102522 is a committed step in wyosine biosynthesis, and its loss leads to unmodified tRNAPhe, which can cause ribosomal frameshifting and proteome instability. In eukaryotes, TYW1 is a radical SAM flavoenzyme, and mutations in its gene have been associated with mitochondrial dysfunction and neurological disease. Understanding this activity provides insights into tRNA biology, translation regulation, and potential therapeutic targets for diseases linked to tRNA modification defects.
• Essential for translational fidelity: wyosine derivatives prevent frameshifting and ensure accurate decoding of phenylalanine codons.
• Linked to mitochondrial function: TYW1 is a mitochondrial protein in eukaryotes, and its dysfunction affects oxidative phosphorylation.
• Implicated in cancer: altered tRNA modification patterns, including wyosine, are observed in various cancers.
• Target for antimicrobials: archaeal Trm5 enzymes are potential targets for developing new antibiotics.
• Model for radical SAM enzymology: TYW1 provides a paradigm for understanding radical SAM flavoenzymes.
• Relevant to ribosomopathies: defects in tRNA modification can lead to ribosome assembly stress and disease.
• Biomarker potential: tRNA modification profiles are emerging as biomarkers for disease diagnosis and prognosis.
• Synthetic biology applications: engineered tRNA modification enzymes can be used to expand the genetic code.
What Happens During tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity?
Substrate recognition and binding
In simple terms: The enzyme finds and grabs the tRNA molecule that needs modification.
The enzyme specifically recognizes tRNAPhe and binds to the anticodon loop, positioning 4-demethylwyosine37 for catalysis. In Archaea, the bifunctional Trm5a/Trm5b enzymes first methylate guanosine at position 37 to form m1G or imG2, then catalyze the aminocarboxypropylation step. Structural studies of Trm5a reveal a conserved tRNA-binding cleft that accommodates the anticodon stem-loop.
Radical SAM activation
In simple terms: The enzyme uses a special iron-sulfur cluster to generate a reactive radical that drives the reaction.
The enzyme belongs to the radical SAM superfamily, which uses a [4Fe-4S] cluster to reductively cleave SAM into methionine and a 5'-deoxyadenosyl radical. This radical then abstracts a hydrogen atom from the substrate, initiating the modification. In Pyrococcus abyssi, the enzyme contains an additional [4Fe-4S] cluster that interacts with pyruvate, which serves as an electron donor.
Aminocarboxypropyl transfer
In simple terms: A chemical group is transferred from SAM to the tRNA base, completing the modification.
Following radical activation, the 3-amino-3-carboxypropyl group from a second SAM molecule is transferred to 4-demethylwyosine37, forming 7-[(3S)-3-amino-3-carboxypropyl]-4-demethylwyosine37. This step releases MTA and a proton. In eukaryotic TYW1, the reaction requires flavin mononucleotide (FMN) or FAD as a cofactor, distinguishing it from the archaeal enzyme.
Product release and tRNA recycling
In simple terms: The modified tRNA is released and can participate in protein synthesis.
After the modification, the tRNAPhe is released from the enzyme and can be aminoacylated and used in translation. The wyosine modification stabilizes the codon-anticodon interaction and prevents frameshifting. The enzyme can then bind another substrate molecule for a new round of catalysis.
Key Genes Involved in GO:0102522 tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity
The following genes and proteins are directly involved in or regulate the activity described by GO:0102522.
| Gene | Major Role | Research Relevance |
|---|---|---|
| TYW1 | Eukaryotic radical SAM flavoenzyme that catalyzes the aminocarboxypropylation of 4-demethylwyosine37 in tRNAPhe | Mutations linked to mitochondrial dysfunction and neurological disorders; target for studying radical SAM mechanisms |
| TYW2 | Methyltransferase that converts 4-demethylwyosine to wybutosine-86 in yeast | Required for complete wyosine biosynthesis; knockout leads to translation defects |
| TYW3 | Methyltransferase involved in wybutosine biosynthesis | Potential modifier of tRNA function; studied in yeast models |
| TYW4 | Hydroxylase/kinase involved in wybutosine maturation | Defects affect tRNA stability and translation |
| TRM5a | Archaeal bifunctional tRNA methyltransferase that catalyzes m1G/imG2 formation and aminocarboxypropylation | Model for understanding bifunctional radical SAM enzymes; structural studies available |
| TRM5b | Archaeal monofunctional methyltransferase that forms m1G at position 37 | Provides insights into substrate specificity and evolution of tRNA modification enzymes |
| PAB_RS03405 | Pyrococcus abyssi gene encoding 4-demethylwyosine synthase | Biochemical characterization of radical SAM enzyme with additional [4Fe-4S] cluster |
| SAM synthase | Produces S-adenosyl-L-methionine, the co-substrate for the reaction | Regulates flux through the wyosine biosynthesis pathway |
| MTA nucleosidase | Recycles 5'-S-methyl-5'-thioadenosine produced by the reaction | Affects cellular methionine salvage and polyamine biosynthesis |
| tRNAPhe | The substrate tRNA that accepts the aminocarboxypropyl group | Its modification status is critical for decoding phenylalanine codons |
| Elongator complex | Regulates tRNA modification and translation efficiency | Cross-talk with wyosine pathway may influence proteostasis |
| Ribosome | Translates modified tRNAPhe; wyosine ensures fidelity | Frameshifting defects observed when modification is lost |
| Mitochondrial import machinery | Translocates TYW1 into mitochondria | Determines subcellular localization and function of TYW1 |
| Iron-sulfur cluster assembly proteins | Maturate the [4Fe-4S] cluster of TYW1 | Defects in cluster assembly impair enzyme activity |
| Flavin reductase | Provides reduced FAD for eukaryotic TYW1 | Modulates TYW1 activity in vivo |
| Pyruvate dehydrogenase | Supplies pyruvate as electron donor for archaeal enzyme | Links central metabolism to tRNA modification |
| tRNA modification enzymes (general) | Coordinate the sequential steps of wyosine biosynthesis | Systems-level studies reveal pathway integration |
How Is tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity Regulated?
The activity of tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase is regulated at multiple levels. In eukaryotes, TYW1 is a mitochondrial protein, and its import and activity may be influenced by mitochondrial metabolic state and iron-sulfur cluster availability. The archaeal enzyme requires pyruvate as a co-substrate, linking its activity to central carbon metabolism. Additionally, the expression of tRNA modification enzymes can be regulated by stress-responsive pathways, such as the integrated stress response, which alters translation and tRNA modification patterns. However, specific regulatory mechanisms for this enzyme remain an active area of research.
tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| TYW1 | Mitochondrial dysfunction, neurological disorders | TYW1 knockout human cell lines; patient-derived fibroblasts |
| TYW1 | Cancer (altered translation) | Cancer cell lines with TYW1 overexpression or knockdown |
| TRM5a/TRM5b | Archaeal tRNA modification; antimicrobial target | Pyrococcus abyssi or Methanocaldococcus jannaschii knockout strains |
| TYW2-4 | Ribosomopathies, translation defects | Yeast deletion mutants and human cell models |
| tRNAPhe | Frameshift-related proteotoxicity | Reporter assays in TYW1-deficient cells |
Mitochondrial dysfunction and neurological disorders
Eukaryotic TYW1 is localized to mitochondria, and its dysfunction has been linked to mitochondrial diseases. Mutations in TYW1 can impair oxidative phosphorylation and lead to neurological symptoms such as encephalopathy and developmental delay. The loss of wyosine modification in tRNAPhe may cause mitochondrial translation defects, contributing to disease pathology.
Cancer
Altered tRNA modification profiles, including changes in wyosine derivatives, have been observed in various cancers. Dysregulation of TYW1 expression or activity may affect translational fidelity and promote tumorigenesis through proteome instability. Targeting tRNA modification pathways is an emerging therapeutic strategy in oncology.
Ribosomopathies and translation-related diseases
Defects in tRNA modification enzymes can lead to ribosome assembly stress and impaired protein synthesis, contributing to ribosomopathies. The wyosine modification is critical for reading-frame maintenance, and its absence can cause frameshifting and proteotoxic stress. Diseases such as Diamond-Blackfan anemia and Shwachman-Diamond syndrome may involve tRNA modification defects.
From tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the catalytic mechanism of TYW1? | Recombinant TYW1 with site-directed mutations in the [4Fe-4S] cluster or FAD-binding site |
| How does loss of TYW1 affect mitochondrial translation? | TYW1 knockout human cell lines (e.g., HEK293T) followed by mitochondrial ribosome profiling |
| Does the wyosine modification prevent frameshifting? | Point mutations in tRNAPhe that disrupt modification, coupled with dual-luciferase frameshift reporters |
| What is the role of pyruvate in archaeal enzyme? | Knock-in of pyruvate-binding site mutations in Pyrococcus abyssi |
| Can TYW1 be targeted for cancer therapy? | Overexpression of TYW1 in cancer cell lines and xenograft models |
| How do tRNA modification enzymes coordinate? | Knockout of multiple TYW genes in yeast and proteomic analysis |
How to Study the tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| HPLC-MS | Formation of modified tRNA bases | In vitro enzyme activity assays |
| X-ray crystallography | Three-dimensional structure of enzyme-tRNA complex | Mechanistic studies of Trm5a/Trm5b |
| Ribo-seq | Ribosome occupancy and frameshifting | Translation fidelity in TYW1 knockout cells |
| tRNA modification mapping | Presence of wyosine derivatives in tRNA | Comparing wild-type and mutant cells |
| Western blot | Protein expression levels | Validating TYW1 knockout or overexpression |
| Immunofluorescence | Subcellular localization | Confirming mitochondrial localization of TYW1 |
| CRISPR screening | Genes required for tRNA modification | Identifying synthetic lethal interactions |
| Mass spectrometry | Proteome-wide changes | Assessing proteostasis upon TYW1 loss |
Biochemical assays for enzyme activity
In vitro assays using recombinant TYW1 and synthetic tRNAPhe substrates can measure the formation of 7-[(3S)-3-amino-3-carboxypropyl]-4-demethylwyosine37 by HPLC or mass spectrometry. These assays require anaerobic conditions to preserve the [4Fe-4S] cluster and may include pyruvate or flavin reductases as electron donors.
Structural biology
X-ray crystallography and cryo-EM can determine the structure of TYW1 or Trm5a in complex with tRNA and SAM analogs. Such studies reveal substrate binding, catalytic residues, and conformational changes during catalysis.
RNA sequencing and modification mapping
tRNA modification mapping techniques, such as m1A-seq or nanopore sequencing, can quantify wyosine levels in wild-type and mutant cells. These methods link enzyme activity to tRNA modification status and translation efficiency.
Ribosome profiling
Ribo-seq measures ribosome occupancy and frameshifting in cells lacking TYW1. It provides a global view of how loss of wyosine modification affects translation fidelity.
How CRISPR Can Be Used to Study GO:0102522 tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity
Knockout
CRISPR-Cas9 knockout of TYW1 in human cell lines (e.g., HEK293T, HeLa) abolishes wyosine modification in tRNAPhe, leading to mitochondrial translation defects and reduced cell proliferation. These models are used to study the physiological consequences of loss of GO:0102522 activity.
Point Mutation
Point mutations in the [4Fe-4S] cluster-binding motifs or FAD-binding site of TYW1 can be introduced via CRISPR base editing or homology-directed repair. Such mutants help dissect the catalytic mechanism and distinguish between radical SAM and flavin-dependent steps.
Knock-in
Knock-in of epitope tags (e.g., FLAG, HA) at the endogenous TYW1 locus enables affinity purification and proteomic analysis of interacting partners. This approach can reveal the composition of the tRNA modification machinery in vivo.
Overexpression
CRISPR activation (CRISPRa) or lentiviral overexpression of TYW1 can increase wyosine levels and enhance mitochondrial translation. Overexpression models are useful for studying gain-of-function effects and for drug screening.
How EDITGENE Supports tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity Research
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Frequently Asked Questions About tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity
What is GO:0102522?
GO:0102522 is a Gene Ontology molecular function term describing the activity of an enzyme that transfers an alpha-amino-alpha-carboxypropyl group from SAM to 4-demethylwyosine37 in tRNAPhe, forming wyosine derivatives.
What genes are involved in tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity?
The main genes are TYW1 in eukaryotes and TRM5a/TRM5b in Archaea. Other genes in the pathway include TYW2, TYW3, and TYW4.
What is the function of TYW1?
TYW1 is a radical SAM flavoenzyme that catalyzes the aminocarboxypropylation of 4-demethylwyosine37 in tRNAPhe, a critical step in wyosine biosynthesis.
How is wyosine modification related to disease?
Loss of wyosine modification can cause mitochondrial dysfunction, neurological disorders, and cancer due to impaired translation fidelity.
What cofactors are required for this enzyme activity?
The enzyme requires a [4Fe-4S] cluster and SAM. Eukaryotic TYW1 also uses FAD, while archaeal enzymes may use pyruvate as an electron donor.
Can I study this pathway using CRISPR?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are available to study TYW1 and related genes.
What methods are used to measure this enzyme activity?
In vitro assays with HPLC-MS, structural biology, Ribo-seq, and tRNA modification mapping are commonly used.
Is TYW1 localized to mitochondria?
Yes, eukaryotic TYW1 is a mitochondrial protein, and its dysfunction affects mitochondrial translation.
What are the substrates of GO:0102522?
The substrates are S-adenosyl-L-methionine and 4-demethylwyosine37 in tRNAPhe.
What are the products of this reaction?
The products are 5'-S-methyl-5'-thioadenosine, H+, and 7-[(3S)-3-amino-3-carboxypropyl]-4-demethylwyosine37 in tRNAPhe.
Conclusion
GO:0102522, tRNA 4-demethylwyosine alpha-amino-alpha-carboxypropyltransferase activity, is a critical enzymatic step in the biosynthesis of wyosine derivatives in tRNAPhe. This radical SAM-dependent reaction ensures translational fidelity and mitochondrial function, and its dysregulation is linked to human diseases. Researchers can leverage CRISPR-based models and advanced analytical methods to dissect the mechanism and therapeutic potential of this pathway. EDITGENE offers comprehensive services to support these investigations.
References
- 1. Young AP et al.. 2021. Eukaryotic TYW1 Is a Radical SAM Flavoenzyme.. Biochemistry 60(27):2179-2185 PMID: 34184886
- 2. Wang C et al.. 2016. Crystal structures of the bifunctional tRNA methyltransferase Trm5a.. Sci Rep 6:33553 PMID: 27629654
- 3. Wu J et al.. 2017. The crystal structure of the Pyrococcus abyssi mono-functional methyltransferase PaTrm5b.. Biochem Biophys Res Commun 493(1):240-245 PMID: 28911863
- 4. Urbonavičius J et al.. 2014. Biosynthesis of wyosine derivatives in tRNA(Phe) of Archaea: role of a remarkable bifunctional tRNA(Phe):m1G/imG2 methyltransferase.. RNA 20(6):747-53 PMID: 24837075
- 5. Perche-Letuvée P et al.. 2012. 4-Demethylwyosine synthase from Pyrococcus abyssi is a radical-S-adenosyl-L-methionine enzyme with an additional [4Fe-4S](+2) cluster that interacts with the pyruvate co-substrate.. J Biol Chem 287(49):41174-85 PMID: 23043105
