Enzymes
| UniProtKB help_outline | 13,142 proteins |
Reaction participants Show >> << Hide
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Namehelp_outline
a tRNA with a 3' CCA end
Identifier
RHEA-COMP:10468
Reactive part
help_outline
- Name help_outline tRNA 3'-terminal nucleotidyl-cytidyl-cytidyl-adenosine residue Identifier CHEBI:83071 Charge -4 Formula C33H41N11O26P4R SMILEShelp_outline Nc1ccn([C@@H]2O[C@H](COP([O-])(=O)O[C@H]3[C@@H](O)[C@@H](O[C@@H]3COP([O-])(=O)O[C@H]3[C@@H](O)[C@H]([*])O[C@@H]3COP([O-])(-*)=O)n3ccc(N)nc3=O)[C@@H](OP([O-])(=O)OC[C@H]3O[C@H]([C@H](O)[C@@H]3O)n3cnc4c(N)ncnc34)[C@H]2O)c(=O)n1 2D coordinates Mol file for the small molecule Search links Involved in 3 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline ATP Identifier CHEBI:30616 (Beilstein: 3581767) help_outline Charge -4 Formula C10H12N5O13P3 InChIKeyhelp_outline ZKHQWZAMYRWXGA-KQYNXXCUSA-J SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OP([O-])([O-])=O)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,256 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline CTP Identifier CHEBI:37563 (Beilstein: 4732530) help_outline Charge -4 Formula C9H12N3O14P3 InChIKeyhelp_outline PCDQPRRSZKQHHS-XVFCMESISA-J SMILEShelp_outline Nc1ccn([C@@H]2O[C@H](COP([O-])(=O)OP([O-])(=O)OP([O-])([O-])=O)[C@@H](O)[C@H]2O)c(=O)n1 2D coordinates Mol file for the small molecule Search links Involved in 78 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
a tRNA with a 3' CCACCA end
Identifier
RHEA-COMP:18655
Reactive part
help_outline
- Name help_outline a tRNA with a 3' CCACCA end Identifier CHEBI:195187 Charge -7 Formula C61H74N22O46P7R SMILEShelp_outline C1=CC(=NC(N1[C@@H]2O[C@H](COP(O[C@H]3[C@H]([C@H](*)O[C@@H]3COP(*)(=O)[O-])O)([O-])=O)[C@H]([C@H]2O)OP(OC[C@H]4O[C@@H](N5C=CC(=NC5=O)N)[C@@H]([C@@H]4OP(OC[C@H]6O[C@@H](N7C8=C(N=C7)C(=NC=N8)N)[C@@H]([C@@H]6OP(OC[C@H]9O[C@@H](N%10C=CC(=NC%10=O)N)[C@@H]([C@@H]9OP(OC[C@H]%11O[C@@H](N%12C=CC(=NC%12=O)N)[C@@H]([C@@H]%11OP(OC[C@H]%13O[C@@H](N%14C%15=C(N=C%14)C(=NC=N%15)N)[C@@H]([C@@H]%13O)O)([O-])=O)O)([O-])=O)O)([O-])=O)O)([O-])=O)O)([O-])=O)=O)N 2D coordinates Mol file for the small molecule Search links Involved in 1 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline diphosphate Identifier CHEBI:33019 (Beilstein: 185088) help_outline Charge -3 Formula HO7P2 InChIKeyhelp_outline XPPKVPWEQAFLFU-UHFFFAOYSA-K SMILEShelp_outline OP([O-])(=O)OP([O-])([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 1,085 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:76235 | RHEA:76236 | RHEA:76237 | RHEA:76238 | |
|---|---|---|---|---|
| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
| UniProtKB help_outline |
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Publications
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On-enzyme refolding permits small RNA and tRNA surveillance by the CCA-adding enzyme.
Kuhn C.D., Wilusz J.E., Zheng Y., Beal P.A., Joshua-Tor L.
Transcription in eukaryotes produces a number of long noncoding RNAs (lncRNAs). Two of these, MALAT1 and MenĪ², generate a tRNA-like small RNA in addition to the mature lncRNA. The stability of these tRNA-like small RNAs and bona fide tRNAs is monitored by the CCA-adding enzyme. Whereas CCA is adde ... >> More
Transcription in eukaryotes produces a number of long noncoding RNAs (lncRNAs). Two of these, MALAT1 and MenĪ², generate a tRNA-like small RNA in addition to the mature lncRNA. The stability of these tRNA-like small RNAs and bona fide tRNAs is monitored by the CCA-adding enzyme. Whereas CCA is added to stable tRNAs and tRNA-like transcripts, a second CCA repeat is added to certain unstable transcripts to initiate their degradation. Here, we characterize how these two scenarios are distinguished. Following the first CCA addition cycle, nucleotide binding to the active site triggers a clockwise screw motion, producing torque on the RNA. This ejects stable RNAs, whereas unstable RNAs are refolded while bound to the enzyme and subjected to a second CCA catalytic cycle. Intriguingly, with the CCA-adding enzyme acting as a molecular vise, the RNAs proofread themselves through differential responses to its interrogation between stable and unstable substrates. << Less
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tRNAs marked with CCACCA are targeted for degradation.
Wilusz J.E., Whipple J.M., Phizicky E.M., Sharp P.A.
The CCA-adding enzyme [ATP(CTP):tRNA nucleotidyltransferase] adds CCA to the 3' ends of transfer RNAs (tRNAs), a critical step in tRNA biogenesis that generates the amino acid attachment site. We found that the CCA-adding enzyme plays a key role in tRNA quality control by selectively marking struc ... >> More
The CCA-adding enzyme [ATP(CTP):tRNA nucleotidyltransferase] adds CCA to the 3' ends of transfer RNAs (tRNAs), a critical step in tRNA biogenesis that generates the amino acid attachment site. We found that the CCA-adding enzyme plays a key role in tRNA quality control by selectively marking structurally unstable tRNAs and tRNA-like small RNAs for degradation. Instead of adding CCA to the 3' ends of these transcripts, CCA-adding enzymes from all three kingdoms of life add CCACCA. In addition, hypomodified mature tRNAs are subjected to CCACCA addition as part of a rapid tRNA decay pathway in vivo. We conjecture that CCACCA addition is a universal mechanism for controlling tRNA levels and preventing errors in translation. << Less