2KC8
Structure of E. coli toxin RelE (R81A/R83A) mutant in complex with antitoxin RelBc (K47-L79) peptide
Summary for 2KC8
| Entry DOI | 10.2210/pdb2kc8/pdb |
| Related | 2KC9 |
| NMR Information | BMRB: 16065 |
| Descriptor | Toxin relE, Antitoxin RelB (2 entities in total) |
| Functional Keywords | protein-protein complex, toxin rele, antitoxin relb, repressor, stress response, toxin, transcription, transcription regulation, toxin-toxin repressor complex, toxin/toxin repressor |
| Biological source | Escherichia coli More |
| Total number of polymer chains | 2 |
| Total formula weight | 15491.99 |
| Authors | Li, G.,Zhang, Y.,Inouye, M.,Ikura, M. (deposition date: 2008-12-17, release date: 2009-03-17, Last modification date: 2024-05-22) |
| Primary citation | Li, G.Y.,Zhang, Y.,Inouye, M.,Ikura, M. Inhibitory mechanism of Escherichia coli RelE-RelB toxin-antitoxin module involves a helix displacement near an mRNA interferase active site. J.Biol.Chem., 284:14628-14636, 2009 Cited by PubMed Abstract: In Escherichia coli, RelE toxin participates in growth arrest and cell death by inducing mRNA degradation at the ribosomal A-site under stress conditions. The NMR structures of a mutant of E. coli RelE toxin, RelE(R81A/R83A), with reduced toxicity and its complex with an inhibitory peptide from RelB antitoxin, RelB(C) (Lys(47)-Leu(79)), have been determined. In the free RelE(R81A/R83A) structure, helix alpha4 at the C terminus adopts a closed conformation contacting with the beta-sheet core and adjacent loops. In the RelE(R81A/R83A)-RelB(C) complex, helix alpha3(*) of RelB(C) displaces alpha4 of RelE(R81A/R83A) from the binding site on the beta-sheet core. This helix replacement results in neutralization of a conserved positively charged cluster of RelE by acidic residues from alpha3(*) of RelB. The released helix alpha4 becomes unfolded, adopting an open conformation with increased mobility. The displacement of alpha4 disrupts the geometry of critical residues, including Arg(81) and Tyr(87), in a putative active site of RelE toxin. Our structures indicate that RelB counteracts the toxic activity of RelE by displacing alpha4 helix from the catalytically competent position found in the free RelE structure. PubMed: 19297318DOI: 10.1074/jbc.M809656200 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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