Enzymes
| UniProtKB help_outline | 9,876 proteins |
Reaction participants Show >> << Hide
- 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 1,280 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
O-(5'-adenylyl)-L-tyrosyl-[protein]
Identifier
RHEA-COMP:13846
Reactive part
help_outline
- Name help_outline L-tyrosine-O-adenyl residue Identifier CHEBI:83624 Charge -1 Formula C19H20N6O8P SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](COP([O-])(=O)Oc2ccc(C[C@H](N-*)C(-*)=O)cc2)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 5 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 1,129 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
O-[5'-(adenylyl-(5'→3')-adenylyl)]-L-tyrosyl-[protein]
Identifier
RHEA-COMP:17046
Reactive part
help_outline
- Name help_outline O-[5'-(adenyl-(5'→3')-adenyl)]-L-tyrosine residue Identifier CHEBI:167160 Charge -2 Formula C29H31N11O14P2 SMILEShelp_outline O(C1=CC=C(C[C@@H](C(*)=O)N*)C=C1)P(=O)(OC[C@H]2O[C@H]([C@@H]([C@@H]2OP(OC[C@H]3O[C@H]([C@@H]([C@@H]3O)O)N4C=NC5=C(N=CN=C54)N)(=O)[O-])O)N6C=NC7=C(N=CN=C76)N)[O-] 2D coordinates Mol file for the small molecule Search links Involved in 2 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:66528 | RHEA:66529 | RHEA:66530 | RHEA:66531 | |
|---|---|---|---|---|
| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
| UniProtKB help_outline |
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Publications
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HEPN-MNT Toxin-Antitoxin System: The HEPN Ribonuclease Is Neutralized by OligoAMPylation.
Songailiene I., Juozapaitis J., Tamulaitiene G., Ruksenaite A., Sulcius S., Sasnauskas G., Venclovas C., Siksnys V.
Prokaryotic toxin-antitoxin (TA) systems are composed of a toxin capable of interfering with key cellular processes and its neutralizing antidote, the antitoxin. Here, we focus on the HEPN-MNT TA system encoded in the vicinity of a subtype I-D CRISPR-Cas system in the cyanobacterium Aphanizomenon ... >> More
Prokaryotic toxin-antitoxin (TA) systems are composed of a toxin capable of interfering with key cellular processes and its neutralizing antidote, the antitoxin. Here, we focus on the HEPN-MNT TA system encoded in the vicinity of a subtype I-D CRISPR-Cas system in the cyanobacterium Aphanizomenon flos-aquae. We show that HEPN acts as a toxic RNase, which cleaves off 4 nt from the 3' end in a subset of tRNAs, thereby interfering with translation. Surprisingly, we find that the MNT (minimal nucleotidyltransferase) antitoxin inhibits HEPN RNase through covalent di-AMPylation (diadenylylation) of a conserved tyrosine residue, Y109, in the active site loop. Furthermore, we present crystallographic snapshots of the di-AMPylation reaction at different stages that explain the mechanism of HEPN RNase inactivation. Finally, we propose that the HEPN-MNT system functions as a cellular ATP sensor that monitors ATP homeostasis and, at low ATP levels, releases active HEPN toxin. << Less
Mol. Cell 0:0-0(2020) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.
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Novel polyadenylylation-dependent neutralization mechanism of the HEPN/MNT toxin/antitoxin system.
Yao J., Zhen X., Tang K., Liu T., Xu X., Chen Z., Guo Y., Liu X., Wood T.K., Ouyang S., Wang X.
The two-gene module HEPN/MNT is predicted to be the most abundant toxin/antitoxin (TA) system in prokaryotes. However, its physiological function and neutralization mechanism remains obscure. Here, we discovered that the MntA antitoxin (MNT-domain protein) acts as an adenylyltransferase and chemic ... >> More
The two-gene module HEPN/MNT is predicted to be the most abundant toxin/antitoxin (TA) system in prokaryotes. However, its physiological function and neutralization mechanism remains obscure. Here, we discovered that the MntA antitoxin (MNT-domain protein) acts as an adenylyltransferase and chemically modifies the HepT toxin (HEPN-domain protein) to block its toxicity as an RNase. Biochemical and structural studies revealed that MntA mediates the transfer of three AMPs to a tyrosine residue next to the RNase domain of HepT in Shewanella oneidensis. Furthermore, in vitro enzymatic assays showed that the three AMPs are transferred to HepT by MntA consecutively with ATP serving as the substrate, and this polyadenylylation is crucial for reducing HepT toxicity. Additionally, the GSX10DXD motif, which is conserved among MntA proteins, is the key active motif for polyadenylylating and neutralizing HepT. Thus, HepT/MntA represents a new type of TA system, and the polyadenylylation-dependent TA neutralization mechanism is prevalent in bacteria and archaea. << Less
Nucleic Acids Res. 48:11054-11067(2020) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.