7CHD image
Deposition Date 2020-07-05
Release Date 2020-11-04
Last Version Date 2023-11-29
Entry Detail
PDB ID:
7CHD
Keywords:
Title:
AtaT complexed with acetyl-methionyl-tRNAfMet
Biological Source:
Source Organism:
Method Details:
Experimental Method:
Resolution:
3.80 Å
R-Value Free:
0.34
R-Value Work:
0.28
R-Value Observed:
0.28
Space Group:
P 21 21 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:N-acetyltransferase domain-containing protein
Gene (Uniprot):Z4832
Mutations:G108D
Chain IDs:A, B, C, D, E, F, G, H
Chain Length:183
Number of Molecules:8
Biological Source:Escherichia coli O157:H7
Polymer Type:polyribonucleotide
Molecule:RNA (77-MER)
Chain IDs:I, J
Chain Length:77
Number of Molecules:2
Biological Source:Escherichia coli
Ligand Molecules
Primary Citation
Mechanism of aminoacyl-tRNA acetylation by an aminoacyl-tRNA acetyltransferase AtaT from enterohemorrhagic E. coli.
Nat Commun 11 5438 5438 (2020)
PMID: 33116145 DOI: 10.1038/s41467-020-19281-z

Abstact

Toxin-antitoxin systems in bacteria contribute to stress adaptation, dormancy, and persistence. AtaT, a type-II toxin in enterohemorrhagic E. coli, reportedly acetylates the α-amino group of the aminoacyl-moiety of initiator Met-tRNAfMet, thus inhibiting translation initiation. Here, we show that AtaT has a broader specificity for aminoacyl-tRNAs than initially claimed. AtaT efficiently acetylates Gly-tRNAGly, Trp-tRNATrp, Tyr-tRNATyr and Phe-tRNAPhe isoacceptors, in addition to Met-tRNAfMet, and inhibits global translation. AtaT interacts with the acceptor stem of tRNAfMet, and the consecutive G-C pairs in the bottom-half of the acceptor stem are required for acetylation. Consistently, tRNAGly, tRNATrp, tRNATyr and tRNAPhe also possess consecutive G-C base-pairs in the bottom halves of their acceptor stems. Furthermore, misaminoacylated valyl-tRNAfMet and isoleucyl-tRNAfMet are not acetylated by AtaT. Therefore, the substrate selection by AtaT is governed by the specific acceptor stem sequence and the properties of the aminoacyl-moiety of aminoacyl-tRNAs.

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Primary Citation of related structures