GO:0002949 tRNA threonylcarbamoyladenosine modification: tRNA Modification Pathway, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0002949 describes the attachment of a threonine and a carbonyl group to the adenine at position 37 of tRNAs that decode ANN codons, forming the universal modification t6A.
• t6A is essential in bacteria and is conserved across all domains of life, where it stabilizes codon-anticodon pairing and supports translational fidelity.
• The modification is installed by the KEOPS complex (Kinase, Endopeptidase and Other Proteins of small size) together with accessory factors such as YRDC, and its catalytic and regulatory basis has been structurally resolved.
• Loss of t6A biosynthesis impairs growth, filamentation, and virulence in fungal pathogens such as Candida albicans, and shapes tRNA modification landscapes in streptococci.
• In cancer, YRDC-mediated t6A modification fuels glioblastoma through threonine-dependent, codon-biased translational reprogramming, linking this tRNA modification to tumor metabolism.
• t6A and its hypermodifications are emerging as disease-relevant nodes, making the pathway an attractive target for CRISPR knockout, point-mutation, and knock-in studies.
Description
GO:0002949, tRNA threonylcarbamoyladenosine modification, is the biological process that installs a threonylcarbamoyl group on the adenine immediately 3' of the anticodon in tRNAs that read ANN codons. This modification, commonly called t6A, is one of the most universal and evolutionarily conserved tRNA modifications known, and it is found in bacteria, archaea, and eukaryotes. Because it sits at the wobble-adjacent position 37, t6A directly influences codon-anticodon interactions and the efficiency and fidelity of protein synthesis. Researchers study GO:0002949 because it connects basic tRNA biology to bacterial essentiality, fungal virulence, and human cancer metabolism. The pathway is also a model for understanding how multi-protein machines such as the KEOPS complex recognize and modify RNA substrates. As tRNA modification landscapes are mapped across species, t6A biosynthesis is increasingly recognized as a hub of translational regulation rather than a static housekeeping event.
tRNA threonylcarbamoyladenosine modification At A Glance
| GO ID | GO:0002949 |
|---|---|
| GO term | tRNA threonylcarbamoyladenosine modification |
| Ontology | biological_process |
| Synonym | t6A biosynthesis; t6A tRNA modification; threonylcarbamoyladenosine formation |
| Major function | Attachment of a carbonyl group and threonine to adenine 3' of the anticodon in ANN-decoding tRNAs |
| Target position | Adenine at position 37 of tRNA |
| Codon specificity | tRNAs that decode ANN codons (N = any base) |
| Conservation | Universal modification found across bacteria, archaea, and eukaryotes |
| Key machinery | KEOPS complex and accessory enzymes such as YRDC |
What Is GO:0002949?
In simple terms, GO:0002949 is the cellular process that adds a threonine-containing chemical tag to a specific adenosine in tRNA. According to the QuickGO definition, it is the attachment of a carbonyl group and a threonine to the amino group of the adenine residue immediately 3' of the anticodon, in tRNAs that decode ANN codons, where N is any base. This reaction produces threonylcarbamoyladenosine, abbreviated t6A, at position 37 of the tRNA.
Why Is tRNA threonylcarbamoyladenosine modification Important in Cell Biology?
GO:0002949 matters because t6A is a universal tRNA modification that tunes translation at the codon-anticodon interface, and disrupting it has measurable consequences for growth, stress responses, and virulence. In bacteria, t6A is essential, making the pathway a potential antibacterial target. In eukaryotic pathogens, loss of t6A biosynthesis reduces filamentation and virulence, linking a single RNA modification to infection biology. In human cancer, YRDC-mediated t6A formation supports codon-biased translation that fuels glioblastoma growth, showing that this modification can be co-opted by tumors. The catalytic and regulatory logic of the KEOPS complex further makes GO:0002949 a tractable system for mechanistic studies of RNA-modifying machines.
• t6A is a universal tRNA modification required for translational fidelity and efficient decoding of ANN codons.
• The pathway is essential in bacteria, highlighting its potential as an antibacterial target.
• Loss of t6A biosynthesis impairs filamentation and virulence in Candida albicans.
• YRDC-mediated t6A modification drives threonine-fueled, codon-biased translation in glioblastoma.
• KEOPS complex structure and regulation provide a mechanistic framework for understanding t6A installation.
• Comparative genomics reveals shared losses and clade-specific adaptations in streptococcal tRNA modification landscapes.
• t6A hypermodifications expand the chemical diversity of tRNA and are linked to disease relevance.
• The modification sits at position 37, adjacent to the anticodon, where it stabilizes codon-anticodon pairing.
• Dysregulation of tRNA modification pathways is increasingly implicated in cancer and metabolic reprogramming.
• CRISPR-based models enable causal testing of t6A pathway genes in diverse cell types.
What Happens During tRNA threonylcarbamoyladenosine modification?
Substrate recognition and tRNA selection
In simple terms: The cell first has to find the right tRNA and the right spot on it.
The t6A machinery specifically targets tRNAs that decode ANN codons and modifies the adenine at position 37, immediately 3' of the anticodon. This position is structurally distinct and is recognized by the biosynthetic enzymes rather than by random chemical reactivity. The specificity for ANN-decoding tRNAs ensures that the modification is placed where it can influence codon-anticodon interactions.
Threonine and bicarbonate activation
In simple terms: The building blocks threonine and bicarbonate are activated so they can be attached to the tRNA.
t6A biosynthesis requires threonine and bicarbonate as substrates, which are activated and conjugated to form the threonylcarbamoyl moiety. The pathway uses a conserved set of enzymes that generate the reactive intermediate before transfer to tRNA. This chemistry distinguishes t6A from simpler methylations and explains why dedicated multi-enzyme systems evolved.
KEOPS complex assembly and catalysis
In simple terms: A protein machine called KEOPS builds and installs the t6A tag.
The KEOPS complex is the central catalyst for t6A installation in eukaryotes and archaea, and its catalytic and regulatory basis has been structurally and biochemically characterized. KEOPS coordinates substrate binding and catalysis to ensure efficient modification of the target adenosine. Accessory factors such as YRDC contribute to the pathway in human cells, linking t6A synthesis to cellular metabolism.
t6A formation and hypermodification
In simple terms: After the basic tag is added, it can be further decorated in some organisms.
Once t6A is installed, some organisms and tRNA species carry hypermodified derivatives that add further chemical complexity. These hypermodifications can fine-tune tRNA function and expand the regulatory repertoire of the modification. The balance between t6A and its hypermodified forms is part of the broader tRNA modification landscape.
Functional consequences for translation
In simple terms: The tag helps the tRNA do its job accurately during protein synthesis.
t6A at position 37 stabilizes codon-anticodon pairing and supports translational fidelity, particularly for ANN codons. Loss of t6A leads to growth defects in bacteria and impaired virulence traits in fungal pathogens. In cancer cells, t6A-dependent translation can be reprogrammed to favor specific codon biases that support tumor growth.
Key Genes Involved in GO:0002949 tRNA threonylcarbamoyladenosine modification
The genes and proteins below are core components, accessory factors, and model-system players associated with GO:0002949 and its regulation.
| Gene | Major Role | Research Relevance |
|---|---|---|
| KEOPS complex subunits | Core catalyst for t6A installation | Structural and mechanistic studies of t6A biosynthesis |
| YRDC | Accessory factor in human t6A pathway | Links t6A to glioblastoma translational reprogramming |
| OSGEP | KEOPS subunit in eukaryotes | Candidate for knockout studies of t6A function |
| TP53RK | KEOPS-associated kinase | Regulatory node in t6A pathway |
| TPRKB | KEOPS subunit | Assembly and stability of the modification machinery |
| LAGE3 | KEOPS subunit | Disease-relevant component of t6A machinery |
| Cgi121 | KEOPS accessory protein | Regulation of KEOPS activity |
| Pcc1 | KEOPS subunit | Structural role in complex assembly |
| BUD32 | KEOPS kinase in yeast models | Functional studies of t6A in fungal systems |
| SUA5 | t6A biosynthesis enzyme in bacteria | Essentiality studies in bacteria |
| YgjD | Bacterial t6A enzyme | Antibacterial target evaluation |
| YeaZ | Bacterial t6A enzyme | Genetic interaction studies |
| YjeE | Bacterial t6A enzyme | Pathway essentiality in bacteria |
| Qri7 | Mitochondrial t6A enzyme | Organellar translation studies |
| tRNA-ANN species | Substrate tRNAs for t6A | Codon-specific translation assays |
| Streptococcal modification genes | Clade-specific tRNA modification adaptations | Comparative genomics of tRNA landscapes |
| Candida albicans t6A genes | Filamentation and virulence | Fungal pathogenesis models |
How Is tRNA threonylcarbamoyladenosine modification Regulated?
The t6A pathway is regulated at multiple levels, including the assembly and activity of the KEOPS complex, which provides a catalytic and regulatory basis for controlled tRNA modification. In human cells, YRDC-mediated t6A formation is coupled to threonine availability and metabolic state, enabling codon-biased translational reprogramming in glioblastoma. Comparative studies in streptococci show that tRNA modification landscapes, including t6A-related genes, undergo shared losses and clade-specific adaptations, indicating evolutionary regulation of the pathway. In Candida albicans, t6A biosynthesis contributes to filamentation and virulence, suggesting that the pathway is integrated into developmental and stress-responsive programs.
tRNA threonylcarbamoyladenosine modification and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| YRDC | Glioblastoma translational reprogramming | Knockout and overexpression in glioblastoma cell lines |
| KEOPS subunits | t6A biosynthesis defects | Point-mutation and knock-in models |
| Candida albicans t6A genes | Filamentation and virulence | Fungal knockout models |
| Bacterial t6A enzymes | Bacterial essentiality | Bacterial knockout and essentiality assays |
| Streptococcal modification genes | Clade-specific tRNA adaptation | Comparative genomics and knockout panels |
t6A modification in glioblastoma
Threonine fuels glioblastoma through YRDC-mediated codon-biased translational reprogramming, directly linking t6A modification to tumor metabolism and growth. This positions the t6A pathway as a potential therapeutic node in cancers with altered threonine handling.
Fungal virulence and t6A
A highly conserved tRNA modification, t6A, contributes to Candida albicans filamentation and virulence, showing that loss of this pathway attenuates key pathogenic traits. This makes t6A biosynthesis a candidate antifungal target.
Bacterial essentiality and antibacterial potential
t6A is essential in bacteria, and disruption of its biosynthesis impairs growth, supporting the pathway as a focus for antibacterial development. The universality of the modification across bacteria makes it a broad-spectrum target concept.
t6A hypermodifications and disease relevance
The biology of tRNA t6A modification and its hypermodifications is increasingly linked to disease relevance, including cancer and metabolic disorders. Understanding these modifications may reveal new biomarkers or intervention points.
From tRNA threonylcarbamoyladenosine modification-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Is a t6A pathway gene essential for growth? | CRISPR knockout in bacterial or mammalian cells |
| Does a specific residue control catalytic activity? | Point-mutation knock-in of KEOPS subunits |
| Can t6A status be monitored in live cells? | Tagged knock-in of pathway components |
| Does overexpression of YRDC alter translation? | Overexpression models in cancer cell lines |
| How does t6A loss affect virulence? | Knockout in Candida albicans |
| How do tRNA modification landscapes differ across strains? | Comparative knockout and sequencing panels |
How to Study the tRNA threonylcarbamoyladenosine modification Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Ribo-seq | Ribosome occupancy and codon-level translation | Detecting codon-biased translation in cancer models |
| RNA-seq | Transcript abundance and tRNA expression | Comparing modification landscapes across strains |
| tRNA modification mapping | Presence and identity of tRNA modifications | Profiling t6A and hypermodifications |
| Proteomics | Global protein expression changes | Linking t6A loss to cellular phenotypes |
| Structural biology | KEOPS complex architecture and catalysis | Mechanistic studies of t6A installation |
| Biochemical assays | Enzyme activity and substrate specificity | Testing catalytic mutants |
| Fungal virulence assays | Filamentation and infection phenotypes | Candida albicans models |
| Bacterial essentiality assays | Growth and viability | Antibacterial target validation |
Ribo-seq and translation profiling
Ribo-seq measures ribosome occupancy and codon-level translation efficiency, making it ideal for detecting the translational consequences of altered t6A modification. In glioblastoma models, Ribo-seq revealed codon-biased translation driven by YRDC-mediated t6A formation.
RNA-seq and tRNA modification mapping
RNA-seq and specialized tRNA sequencing approaches can reveal changes in tRNA abundance and modification landscapes across species and strains. Comparative analyses in streptococci demonstrated shared losses and clade-specific adaptations in tRNA modification genes.
Proteomics and metabolic labeling
Proteomics can quantify global changes in protein output when t6A biosynthesis is disrupted, linking the modification to cellular phenotypes. Metabolic labeling with threonine can trace substrate flux into the t6A pathway.
Structural and biochemical assays
Structural studies of the KEOPS complex and its regulatory basis provide mechanistic insight into t6A catalysis. Biochemical assays using purified components can test substrate specificity and catalytic mutants.
How CRISPR Can Be Used to Study GO:0002949 tRNA threonylcarbamoyladenosine modification
Knockout
CRISPR knockout of t6A pathway genes such as KEOPS subunits or YRDC allows causal testing of their role in translation and disease phenotypes. Knockout models in bacteria and fungi can reveal essentiality and virulence contributions.
Point Mutation
Point-mutation knock-in of catalytic residues in KEOPS subunits can dissect the enzymatic mechanism of t6A installation. Such models help distinguish catalytic activity from scaffolding functions.
Knock-in
Tagged knock-in of pathway components enables localization and interaction studies of the t6A machinery in living cells. Knock-in of disease-associated variants can test their impact on tRNA modification.
Overexpression
Overexpression of YRDC or other pathway genes can model the translational reprogramming observed in glioblastoma and other cancers. Overexpression studies help identify dose-dependent effects on codon-biased translation.
How EDITGENE Supports tRNA threonylcarbamoyladenosine modification Research
Researchers studying tRNA threonylcarbamoyladenosine modification-related genes often need to determine whether a candidate gene is causally involved in tRNA modification, translation, or disease phenotypes. EDITGENE provides CRISPR-based cell models and screening services to test these hypotheses directly.
Contact EDITGENE today to design your custom CRISPR model for tRNA threonylcarbamoyladenosine modification research.
Frequently Asked Questions About tRNA threonylcarbamoyladenosine modification
What is tRNA threonylcarbamoyladenosine modification?
It is the attachment of a carbonyl group and a threonine to the adenine at position 37 of tRNAs that decode ANN codons, forming the t6A modification.
What is GO:0002949?
GO:0002949 is the Gene Ontology biological process term for tRNA threonylcarbamoyladenosine modification, also known as t6A biosynthesis.
What genes are involved in tRNA threonylcarbamoyladenosine modification?
Key genes include KEOPS complex subunits, YRDC, and bacterial enzymes such as SUA5, YgjD, YeaZ, and YjeE.
Why is t6A modification important?
t6A stabilizes codon-anticodon pairing, supports translational fidelity, and is essential in bacteria and important for fungal virulence and cancer translation.
Which tRNAs are modified by t6A?
tRNAs that decode ANN codons, where N is any base, are the substrates for t6A modification.
Is t6A modification conserved across species?
Yes, t6A is a universal modification found in bacteria, archaea, and eukaryotes.
How is t6A modification linked to cancer?
YRDC-mediated t6A modification fuels glioblastoma through threonine-dependent, codon-biased translational reprogramming.
What is the KEOPS complex?
The KEOPS complex is the central enzyme machinery that catalyzes t6A installation, and its catalytic and regulatory basis has been characterized.
Can t6A modification be studied with CRISPR?
Yes, CRISPR knockout, point-mutation, knock-in, and overexpression models can test the function of t6A pathway genes.
What methods are used to study t6A modification?
Ribo-seq, RNA-seq, tRNA modification mapping, proteomics, structural biology, and biochemical assays are commonly used.
Conclusion
GO:0002949, tRNA threonylcarbamoyladenosine modification, is a conserved and functionally critical tRNA modification that sits at the interface of translation, metabolism, and disease. Its installation by the KEOPS complex and accessory factors such as YRDC influences codon-anticodon pairing, bacterial essentiality, fungal virulence, and cancer translational reprogramming. As tRNA modification landscapes continue to be mapped, t6A biology offers fertile ground for mechanistic and therapeutic research.
References
- 1. Thiaville PC et al.. 2014. Diversity of the biosynthesis pathway for threonylcarbamoyladenosine (t(6)A), a universal modification of tRNA.. RNA Biol 11(12):1529-39 PMID: 25629598
- 2. Wu X et al.. 2024. Threonine fuels glioblastoma through YRDC-mediated codon-biased translational reprogramming.. Nat Cancer 5(7):1024-1044 PMID: 38519786
- 3. Thiaville PC et al.. 2015. Essentiality of threonylcarbamoyladenosine (t(6)A), a universal tRNA modification, in bacteria.. Mol Microbiol 98(6):1199-221 PMID: 26337258
- 4. Tsui HT et al.. 2025. tRNA Modification Landscapes in Streptococci: Shared Losses and Clade-Specific Adaptations.. bioRxiv PMID: 41280037
- 5. Zhang W et al.. 2025. The Biology of tRNA t(6)A Modification and Hypermodifications-Biogenesis and Disease Relevance.. J Mol Biol 437(16):169091 PMID: 40155300
- 6. Zhou L et al.. 2026. Catalytic and regulatory basis of tRNA t(6)A modification by the KEOPS complex.. Nat Commun 17(1) PMID: 42140986
- 7. Böttcher B et al.. 2024. A highly conserved tRNA modification contributes to C. albicans filamentation and virulence.. Microbiol Spectr 12(5):e0425522 PMID: 38587411
- 8. Tsui HT et al.. 2026. tRNA modification landscapes in streptococci: shared losses and clade-specific adaptations.. Open Biol 16(4) PMID: 41980722
