GO:0016426 tRNA (adenine) methyltransferase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0016426 describes the enzymatic activity that transfers a methyl group from S-adenosyl-L-methionine (SAM) onto an adenine base within tRNA, producing S-adenosyl-L-homocysteine and methyladenine-containing tRNA.
• This activity is best characterized for adenine-N1 methylation (m1A) at tRNA positions such as position 22 and position 9, catalyzed by enzymes including TrmK and N1-adenine methyltransferases.
• tRNA (adenine) methyltransferase activity is conserved from bacteria to humans and has been purified and biochemically characterized from organisms such as Thermus flavus, Thermus thermophilus, and Dictyostelium discoideum.
• Loss of N1-adenine methyltransferase activity aggravates RNA and protein aggregation, linking this modification to RNA stability and proteostasis.
• ALKBH8, a tRNA-modifying enzyme, supports codon-specific translation and promotes colorectal tumorigenesis, showing that tRNA methylation pathways are relevant to cancer biology.
• TRMT112 acts as a common partner of several methyltransferases and regulates expression of N6AMT1 isoforms, indicating that tRNA (adenine) methyltransferase activity is coordinated within larger methyltransferase complexes.
Description
GO:0016426, tRNA (adenine) methyltransferase activity, is a molecular function that catalyzes the transfer of a methyl group from S-adenosyl-L-methionine (SAM) to an adenine residue in tRNA, yielding S-adenosyl-L-homocysteine and tRNA containing methyladenine. This activity introduces chemical marks such as N1-methyladenosine (m1A) into the tRNA molecule, which can influence tRNA folding, stability, and decoding function. Because tRNA modifications are central to faithful protein synthesis, enzymes carrying this activity are studied across bacteriology, cancer biology, and neurobiology. The activity has been biochemically defined through purification and characterization of tRNA (adenine-N1)-methyltransferases from organisms including Dictyostelium discoideum, Thermus flavus, and Thermus thermophilus. These studies established that the enzyme uses SAM as the methyl donor and modifies adenine within tRNA, producing methyladenine-containing tRNA. More recent structural and functional work has focused on bacterial m1A22-tRNA methyltransferase TrmK and on mammalian methyltransferase complexes that include TRMT112 and N6AMT1. For researchers, GO:0016426 matters because perturbations of tRNA adenine methylation can affect translation, RNA aggregation, and tumorigenesis. Understanding which enzymes carry this activity, how they are regulated, and which tRNA substrates they modify is therefore essential for interpreting gene expression phenotypes and for designing CRISPR-based models of tRNA modification biology.
tRNA (adenine) methyltransferase activity At A Glance
| GO ID | GO:0016426 |
|---|---|
| GO term | tRNA (adenine) methyltransferase activity |
| Ontology | molecular_function |
| Synonym | tRNA (adenine-C2-)-methyltransferase activity |
| Major function | Catalyzes methyl transfer from S-adenosyl-L-methionine to adenine in tRNA, producing S-adenosyl-L-homocysteine and methyladenine-containing tRNA |
| Reaction | S-adenosyl-L-methionine + tRNA = S-adenosyl-L-homocysteine + tRNA containing methyladenine |
| Representative enzymes | tRNA (adenine-N1)-methyltransferases such as TrmK and N1-adenine methyltransferases |
| Conservation | Detected in bacteria, protists, and mammals, including Thermus flavus, Thermus thermophilus, Dictyostelium discoideum, and human cells |
| Related modification | N1-methyladenosine (m1A) in tRNA |
What Is GO:0016426?
In simple terms, GO:0016426 is the enzyme activity that puts a methyl tag onto an adenine letter inside a tRNA molecule, using SAM as the methyl donor. The official QuickGO definition states: Catalysis of the reaction: S-adenosyl-L-methionine + tRNA = S-adenosyl-L-homocysteine + tRNA containing methyladenine. A synonym for this activity is tRNA (adenine-C2-)-methyltransferase activity. The activity is a molecular_function in the Gene Ontology and is carried out by enzymes such as tRNA (adenine-N1)-methyltransferases that modify adenine residues within tRNA.
Why Is tRNA (adenine) methyltransferase activity Important in Cell Biology?
tRNA (adenine) methyltransferase activity is important because the methyl marks it installs on tRNA adenine residues influence tRNA structure and function, and loss of this activity can aggravate RNA and protein aggregation. In cancer, tRNA-modifying enzymes such as ALKBH8 support codon-specific translation and promote colorectal tumorigenesis, highlighting the clinical relevance of tRNA methylation pathways. In addition, the activity is integrated into methyltransferase complexes through shared partners such as TRMT112, which regulates expression of N6AMT1 isoforms. Together, these findings make GO:0016426 a meaningful target for studies of translation control, proteostasis, and disease mechanisms.
• Defines a conserved enzymatic step that introduces methyladenine into tRNA, affecting tRNA maturation and function.
• Provides a biochemical basis for studying N1-methyladenosine (m1A) and related tRNA modifications.
• Links tRNA modification to proteostasis, because deficiency of N1-adenine methyltransferase aggravates RNA and protein aggregation.
• Connects tRNA methylation to cancer biology through ALKBH8-mediated codon-specific translation in colorectal tumorigenesis.
• Highlights shared methyltransferase machinery, as TRMT112 partners with multiple methyltransferases and regulates N6AMT1 isoform expression.
• Supports structural and inhibitor studies of bacterial TrmK, relevant to antimicrobial target discovery.
• Enables comparative enzymology across Thermus flavus, Thermus thermophilus, and Dictyostelium discoideum.
• Guides CRISPR model design for testing causal roles of tRNA methyltransferases in translation and disease.
Molecular Mechanism of tRNA (adenine) methyltransferase activity
Substrate recognition and SAM binding
In simple terms: The enzyme first grabs its two main ingredients: a tRNA molecule and a methyl donor called SAM.
tRNA (adenine) methyltransferase activity requires S-adenosyl-L-methionine (SAM) as the methyl donor and a tRNA substrate containing the target adenine. Purification and characterization of tRNA (adenine-N1)-methyltransferases from Thermus flavus and Thermus thermophilus established that these enzymes act on tRNA and depend on SAM for methyl transfer. In Dictyostelium discoideum, tRNA (adenine-N1)-methyltransferase activity was purified and shown to change during development, indicating that substrate recognition and enzyme availability are developmentally regulated.
Catalytic methyl transfer to adenine
In simple terms: The enzyme moves a methyl group from SAM onto a specific adenine in the tRNA.
The catalytic step of GO:0016426 converts SAM and tRNA into S-adenosyl-L-homocysteine and tRNA containing methyladenine. Structural and biochemical work on the Staphylococcus aureus m1A22-tRNA methyltransferase TrmK has provided insight into how this methyl transfer is achieved and how it can be inhibited. The reaction is therefore a classic methyltransferase chemistry in which the adenine base within tRNA is the acceptor for the methyl group.
Formation of methyladenine-containing tRNA
In simple terms: After the methyl group is added, the tRNA carries a new methyladenine mark.
The product of the reaction is tRNA containing methyladenine, which can correspond to N1-methyladenosine (m1A) at defined positions such as position 22 in bacterial tRNA. This modification can influence tRNA folding and decoding, and its loss has been linked to RNA and protein aggregation. The presence of methyladenine in tRNA is thus a direct molecular outcome of GO:0016426.
Enzyme complexes and partner proteins
In simple terms: Some of these enzymes do not work alone; they team up with partner proteins.
TRMT112 is a common partner of several methyltransferases and regulates the expression of N6AMT1 isoforms in mammalian cells, showing that tRNA (adenine) methyltransferase activity can be embedded in multi-protein complexes. In bacteria, TrmK functions as an m1A22-tRNA methyltransferase, and its structure and dynamics have been analyzed to understand its catalytic cycle and inhibition. These partnerships and structural features help determine when and where the activity is deployed.
Regulation by developmental and cellular context
In simple terms: The amount of this enzyme activity can go up or down depending on the cell's state.
Developmental changes in tRNA (adenine-N1)-methyltransferase activity were observed in Dictyostelium discoideum, indicating that this activity is not constant but is tuned during development. In mammalian cells, TRMT112 influences the expression of N6AMT1 isoforms, providing a layer of regulation at the level of methyltransferase complex composition. Such context-dependent regulation can affect the abundance of methyladenine-containing tRNA and downstream translation.
Key Genes Involved in GO:0016426 tRNA (adenine) methyltransferase activity
The following genes and proteins are directly associated with tRNA (adenine) methyltransferase activity or with the methyltransferase complexes that carry it out, based on the verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| TRMK | Bacterial m1A22-tRNA methyltransferase that catalyzes adenine methylation in tRNA | Structural, dynamics, and inhibitor studies in Staphylococcus aureus |
| TRMT112 | Common partner of several methyltransferases; regulates N6AMT1 isoform expression | Studying methyltransferase complex assembly and regulation in mammalian cells |
| N6AMT1 | Methyltransferase whose isoform expression is regulated by TRMT112 | Investigating N6AMT1 isoform biology and tRNA methylation |
| ALKBH8 | tRNA-modifying enzyme supporting codon-specific translation | Cancer research, especially colorectal tumorigenesis |
| N1-adenine methyltransferase (unnamed in citation) | Enzyme whose deficiency aggravates RNA and protein aggregation | Proteostasis and RNA aggregation studies |
| tRNA (adenine-N1)-methyltransferase from Dictyostelium discoideum | Developmental regulated tRNA adenine methyltransferase | Developmental biology and enzyme purification |
| tRNA (adenine-1-)-methyltransferase from Thermus flavus | Purified and characterized tRNA adenine methyltransferase | Comparative enzymology and thermophile biology |
| tRNA(adenine-1-)-methyltransferase from Thermus thermophilus | tRNA adenine methyltransferase from a thermophilic bacterium | Biochemical characterization and thermostability studies |
| METTL3 | Component of the METTL3-METTL14 complex that methylates N6-adenosine | Structural basis of adenine methylation by a related methyltransferase complex |
| METTL14 | Component of the METTL3-METTL14 complex that methylates N6-adenosine | Structural and mechanistic studies of adenine methylation |
| TrmK (Staphylococcus aureus) | m1A22-tRNA methyltransferase | Antimicrobial target exploration |
| TRMT112-associated methyltransferases | Partners in methyltransferase complexes | Understanding shared subunits in tRNA modification |
| N6AMT1 isoforms | Alternatively expressed forms regulated by TRMT112 | Isoform-specific functional studies |
| ALKBH8-dependent translation machinery | Supports codon-specific translation | Translation profiling in cancer models |
| RNA aggregation-prone proteins | Affected by loss of N1-adenine methyltransferase | Aggregation and neurodegeneration-related research |
| SAM-dependent methyltransferases | Use S-adenosyl-L-methionine as methyl donor | General methyltransferase enzymology |
| tRNA substrates with adenine modifications | Carry methyladenine after the reaction | tRNA modification mapping and functional studies |
How Is tRNA (adenine) methyltransferase activity Regulated?
The activity of tRNA (adenine) methyltransferases is regulated at multiple levels. Developmental changes in tRNA (adenine-N1)-methyltransferase activity have been documented in Dictyostelium discoideum, showing that enzyme activity is modulated during the life cycle. In mammalian cells, TRMT112 acts as a common partner of several methyltransferases and regulates the expression of N6AMT1 isoforms, indicating that complex composition and partner availability influence methyltransferase output. In addition, the presence of ALKBH8-dependent tRNA modification supports codon-specific translation, suggesting that tRNA methylation pathways are integrated with translation demand and cancer-related signaling. Loss of N1-adenine methyltransferase activity aggravates RNA and protein aggregation, further implying that cellular stress and proteostasis pathways intersect with this activity.
tRNA (adenine) methyltransferase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| ALKBH8 | Colorectal tumorigenesis and codon-specific translation | Knockout or overexpression in colorectal cancer cell lines followed by Ribo-seq |
| N1-adenine methyltransferase | RNA and protein aggregation | Knockout cells with aggregation assays and proteomics |
| TRMK (Staphylococcus aureus) | Bacterial tRNA methylation and antimicrobial targeting | Bacterial knockout and inhibitor testing |
| TRMT112 | Regulation of N6AMT1 isoform expression | Knockdown or knockout in mammalian cells with isoform-specific assays |
| N6AMT1 | Methyltransferase isoform biology | Isoform-specific overexpression and knockout models |
Cancer and codon-specific translation
ALKBH8-mediated codon-specific translation promotes colorectal tumorigenesis, linking tRNA modification pathways to cancer development. This suggests that enzymes and pathways related to tRNA (adenine) methyltransferase activity may influence tumor cell translation and growth.
RNA and protein aggregation
Deficiency of N1-adenine methyltransferase aggravates RNA and protein aggregation, connecting loss of this type of methyltransferase activity to proteostasis imbalance. Such aggregation phenotypes are relevant to neurodegenerative and stress-related disease models.
Infectious disease and antimicrobial targets
The Staphylococcus aureus m1A22-tRNA methyltransferase TrmK has been structurally and dynamically characterized, and its molecular inhibition has been explored. This makes bacterial tRNA adenine methyltransferases potential targets for antimicrobial development.
Methyltransferase complex dysfunction
TRMT112 regulates the expression of N6AMT1 isoforms in mammalian cells, and disruption of such shared methyltransferase partners could affect multiple tRNA modification pathways. This highlights the importance of complex-level regulation in disease-relevant methyltransferase biology.
From tRNA (adenine) methyltransferase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of a tRNA adenine methyltransferase cause translation defects? | CRISPR knockout cell line followed by Ribo-seq and polysome profiling |
| Does a specific catalytic residue mediate methyl transfer? | Point-mutation knock-in of the catalytic residue with biochemical methyltransferase assays |
| Does tagging the enzyme affect its localization or interactions? | Tagged knock-in with fluorescence imaging and immunoprecipitation |
| Does overexpression of the enzyme alter tRNA modification levels? | Overexpression cell model with tRNA modification mapping |
| Does the enzyme contribute to tumorigenesis? | Knockout or overexpression in cancer cell lines and xenograft models |
| Does the enzyme regulate aggregation phenotypes? | Knockout cells combined with aggregation and proteostasis assays |
How to Study the tRNA (adenine) methyltransferase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| SAM-dependent methyltransferase assay | Methyl transfer from SAM to tRNA | Confirming GO:0016426 activity in purified enzyme preparations |
| tRNA modification mapping | Presence and position of methyladenine in tRNA | Linking enzyme activity to tRNA marks |
| Ribo-seq | Codon-specific translation efficiency | Studying ALKBH8-dependent translation in cancer cells |
| Aggregation assays | RNA and protein aggregation | Evaluating proteostasis defects after methyltransferase loss |
| Structural biology (crystallography/cryo-EM) | Enzyme-substrate interactions and catalytic site architecture | Understanding mechanism and inhibitor design |
| Immunoprecipitation and proteomics | Protein-protein interactions of methyltransferase complexes | Identifying partners such as TRMT112 |
| Isoform-specific expression assays | N6AMT1 isoform levels | Studying TRMT112-dependent regulation |
| Inhibitor testing | Enzymatic activity in the presence of small molecules | Antimicrobial target validation for TrmK |
Biochemical methyltransferase assays
Purification and characterization of tRNA (adenine-N1)-methyltransferases from Thermus flavus, Thermus thermophilus, and Dictyostelium discoideum used classical enzyme assays to measure methyl transfer from SAM to tRNA. These assays remain foundational for confirming GO:0016426 activity in recombinant or purified enzyme preparations.
Structural biology and dynamics
Structural and dynamic studies of the Staphylococcus aureus m1A22-tRNA methyltransferase TrmK have revealed how the enzyme binds substrates and how it can be inhibited. The structural basis of N6-adenosine methylation by the METTL3-METTL14 complex provides a related framework for understanding adenine methylation chemistry.
tRNA modification mapping and sequencing
Detecting methyladenine in tRNA requires methods that can map modifications to specific tRNA positions. Such mapping is essential to connect enzyme activity to the presence of methyladenine-containing tRNA in cells.
Translation profiling and proteostasis assays
Ribo-seq and related translation profiling methods can measure codon-specific translation effects linked to tRNA modification enzymes such as ALKBH8. Aggregation assays and proteomics can assess RNA and protein aggregation phenotypes caused by loss of N1-adenine methyltransferase activity.
How CRISPR Can Be Used to Study GO:0016426 tRNA (adenine) methyltransferase activity
Knockout
CRISPR knockout of genes encoding tRNA adenine methyltransferases can test whether loss of GO:0016426 activity causes translation defects, RNA aggregation, or altered tumorigenesis. For example, knocking out ALKBH8 or N1-adenine methyltransferase allows researchers to measure downstream effects on codon-specific translation and proteostasis.
Point Mutation
Point-mutation knock-in of catalytic residues in tRNA methyltransferases can separate enzymatic activity from scaffolding functions. Such models are useful for testing whether methyl transfer chemistry is required for observed phenotypes.
Knock-in
Tagged knock-in of endogenous methyltransferase genes enables visualization and interaction studies without overexpression artifacts. This approach can reveal where and when the enzyme acts within cells and which partners it engages.
Overexpression
Overexpression of tRNA adenine methyltransferases or their partners can test gain-of-function effects on tRNA modification levels and translation. Overexpression models are particularly useful for studying enzymes such as ALKBH8 in cancer cell contexts.
How EDITGENE Supports tRNA (adenine) methyltransferase activity Research
Researchers studying tRNA (adenine) methyltransferase activity-related genes often need to determine whether a candidate gene is causally involved in tRNA modification, translation, or disease phenotypes. Rigorous causal testing requires well-controlled CRISPR models that isolate the enzymatic activity from secondary effects, combined with quantitative readouts of tRNA methylation and translation.
Contact EDITGENE today to design your custom CRISPR model for tRNA (adenine) methyltransferase activity research.
Frequently Asked Questions About tRNA (adenine) methyltransferase activity
What is tRNA (adenine) methyltransferase activity?
It is the enzyme activity defined by GO:0016426 that transfers a methyl group from S-adenosyl-L-methionine to an adenine in tRNA, producing S-adenosyl-L-homocysteine and methyladenine-containing tRNA.
What is the GO ID for tRNA (adenine) methyltransferase activity?
The GO ID is GO:0016426, and the ontology aspect is molecular_function.
What reaction does GO:0016426 catalyze?
It catalyzes the reaction S-adenosyl-L-methionine + tRNA = S-adenosyl-L-homocysteine + tRNA containing methyladenine.
What genes are involved in tRNA (adenine) methyltransferase activity?
Genes and proteins include TRMK, TRMT112, N6AMT1, ALKBH8, and N1-adenine methyltransferases, as well as characterized enzymes from Thermus flavus, Thermus thermophilus, and Dictyostelium discoideum.
Which modification is produced by tRNA (adenine) methyltransferase activity?
The activity produces methyladenine in tRNA, which can correspond to N1-methyladenosine (m1A) at specific positions such as position 22 in bacterial tRNA.
Why is tRNA (adenine) methyltransferase activity important in cancer?
ALKBH8-mediated codon-specific translation promotes colorectal tumorigenesis, linking tRNA modification pathways to cancer biology.
What happens when N1-adenine methyltransferase is deficient?
Deficiency of N1-adenine methyltransferase aggravates RNA and protein aggregation, indicating a role in proteostasis.
How is tRNA (adenine) methyltransferase activity studied experimentally?
It is studied using SAM-dependent methyltransferase assays, tRNA modification mapping, structural biology, Ribo-seq, aggregation assays, and proteomics.
What is the role of TRMT112 in tRNA methylation?
TRMT112 is a common partner of several methyltransferases and regulates the expression of N6AMT1 isoforms in mammalian cells.
Can CRISPR be used to study tRNA (adenine) methyltransferase activity?
Yes, CRISPR knockout, point-mutation, knock-in, and overexpression models can be used to test causal roles of tRNA methyltransferases in translation and disease phenotypes.
Conclusion
GO:0016426, tRNA (adenine) methyltransferase activity, defines a conserved enzymatic function that methylates adenine in tRNA using SAM as the methyl donor. This activity produces methyladenine-containing tRNA and is carried out by enzymes such as TrmK and N1-adenine methyltransferases, with regulation through partners like TRMT112. The biological importance of this activity spans translation control, proteostasis, cancer, and bacterial physiology, making it a compelling target for mechanistic and therapeutic research. Researchers can now interrogate this activity with CRISPR-based knockout, point-mutation, knock-in, and overexpression models combined with tRNA modification mapping, Ribo-seq, and proteomics. Such integrated approaches will help clarify how tRNA adenine methylation shapes gene expression in health and disease.
References
- 1. Qian Y et al.. 2025. ALKBH8-mediated codon-specific translation promotes colorectal tumorigenesis.. Nat Commun 16(1):9075 PMID: 41083459
- 2. Alriquet M et al.. 2025. Deficiency of N1-Adenine Methyltransferase Aggravates RNA and Protein Aggregation.. Cells 14(17) PMID: 40940780
- 3. Mutzel R et al.. 1986. tRNA (adenine-N1)-methyltransferase from Dictyostelium discoideum. Purification, characterization and developmental changes in activity.. Eur J Biochem 160(1):101-8 PMID: 3769915
- 4. Leetsi L et al.. 2019. The Common Partner of Several Methyltransferases TRMT112 Regulates the Expression of N6AMT1 Isoforms in Mammalian Cells.. Biomolecules 9(9) PMID: 31466382
- 5. Wang X et al.. 2016. Structural basis of N(6)-adenosine methylation by the METTL3-METTL14 complex.. Nature 534(7608):575-8 PMID: 27281194
- 6. Morozov IA et al.. 1982. Purification and characterization of tRNA (adenine-1-)-methyltransferase from Thermus flavus strain 71.. Eur J Biochem 129(2):429-36 PMID: 7151806
- 7. Sweeney P et al.. 2022. Structure, dynamics, and molecular inhibition of the Staphylococcus aureus m(1)A22-tRNA methyltransferase TrmK.. J Biol Chem 298(6):102040 PMID: 35595101
- 8. Morozov IA et al.. 1984. [tRNA(adenine-1-)-methyltransferase from Thermus thermophilus HB8].. Mol Biol (Mosk) 18(5):1363-8 PMID: 6504039
