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Yorodumi- PDB-8ext: Cryo-EM structure of S. aureus BlaR1 F284A mutant in complex with... -
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-Basic information
Entry | Database: PDB / ID: 8ext | ||||||
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Title | Cryo-EM structure of S. aureus BlaR1 F284A mutant in complex with ampicillin | ||||||
Components | Beta-lactam sensor/signal transducer BlaR1 | ||||||
Keywords | SIGNALING PROTEIN/ANTIBIOTIC / Antibiotic resistance / beta-lactam antibiotics / MRSA / BlaR1 / MecR1 / cryo-EM / transmembrane signalling / SIGNALING PROTEIN-ANTIBIOTIC complex | ||||||
Function / homology | Function and homology information | ||||||
Biological species | Staphylococcus aureus (bacteria) | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 4.6 Å | ||||||
Authors | Alexander, J.A.N. / Hu, J. / Worrall, L.J. / Strynadka, N.C.J. | ||||||
Funding support | Canada, 1items
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Citation | Journal: Nature / Year: 2023 Title: Structural basis of broad-spectrum β-lactam resistance in Staphylococcus aureus. Authors: J Andrew N Alexander / Liam J Worrall / Jinhong Hu / Marija Vuckovic / Nidhi Satishkumar / Raymond Poon / Solmaz Sobhanifar / Federico I Rosell / Joshua Jenkins / Daniel Chiang / Wesley A ...Authors: J Andrew N Alexander / Liam J Worrall / Jinhong Hu / Marija Vuckovic / Nidhi Satishkumar / Raymond Poon / Solmaz Sobhanifar / Federico I Rosell / Joshua Jenkins / Daniel Chiang / Wesley A Mosimann / Henry F Chambers / Mark Paetzel / Som S Chatterjee / Natalie C J Strynadka / Abstract: Broad-spectrum β-lactam antibiotic resistance in Staphylococcus aureus is a global healthcare burden. In clinical strains, resistance is largely controlled by BlaR1, a receptor that senses β- ...Broad-spectrum β-lactam antibiotic resistance in Staphylococcus aureus is a global healthcare burden. In clinical strains, resistance is largely controlled by BlaR1, a receptor that senses β-lactams through the acylation of its sensor domain, inducing transmembrane signalling and activation of the cytoplasmic-facing metalloprotease domain. The metalloprotease domain has a role in BlaI derepression, inducing blaZ (β-lactamase PC1) and mecA (β-lactam-resistant cell-wall transpeptidase PBP2a) expression. Here, overcoming hurdles in isolation, we show that BlaR1 cleaves BlaI directly, as necessary for inactivation, with no requirement for additional components as suggested previously. Cryo-electron microscopy structures of BlaR1-the wild type and an autocleavage-deficient F284A mutant, with or without β-lactam-reveal a domain-swapped dimer that we suggest is critical to the stabilization of the signalling loops within. BlaR1 undergoes spontaneous autocleavage in cis between Ser283 and Phe284 and we describe the catalytic mechanism and specificity underlying the self and BlaI cleavage. The structures suggest that allosteric signalling emanates from β-lactam-induced exclusion of the prominent extracellular loop bound competitively in the sensor-domain active site, driving subsequent dynamic motions, including a shift in the sensor towards the membrane and accompanying changes in the zinc metalloprotease domain. We propose that this enhances the expulsion of autocleaved products from the active site, shifting the equilibrium to a state that is permissive of efficient BlaI cleavage. Collectively, this study provides a structure of a two-component signalling receptor that mediates action-in this case, antibiotic resistance-through the direct cleavage of a repressor. | ||||||
History |
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-Structure visualization
Structure viewer | Molecule: MolmilJmol/JSmol |
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-Downloads & links
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PDBx/mmCIF format | 8ext.cif.gz | 200.5 KB | Display | PDBx/mmCIF format |
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PDB format | pdb8ext.ent.gz | 158.8 KB | Display | PDB format |
PDBx/mmJSON format | 8ext.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 8ext_validation.pdf.gz | 1.1 MB | Display | wwPDB validaton report |
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Full document | 8ext_full_validation.pdf.gz | 1.1 MB | Display | |
Data in XML | 8ext_validation.xml.gz | 43.8 KB | Display | |
Data in CIF | 8ext_validation.cif.gz | 65.1 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/ex/8ext ftp://data.pdbj.org/pub/pdb/validation_reports/ex/8ext | HTTPS FTP |
-Related structure data
Related structure data | 28662MC 8expC 8exqC 8exrC 8exsC M: map data used to model this data C: citing same article (ref.) |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
-Assembly
Deposited unit |
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1 |
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-Components
#1: Protein | Mass: 71193.602 Da / Num. of mol.: 2 / Mutation: F284A Source method: isolated from a genetically manipulated source Source: (gene. exp.) Staphylococcus aureus (bacteria) Gene: blaR1, blaR, BN1321_410015, BSZ10_11995, BTN44_15560, FA040_05105, GO941_06445, NCTC13131_00091, SAMEA2077334_00715, SAMEA2078260_01199, SAMEA2078588_01099, SAMEA2080344_00713, SAMEA2081063_ ...Gene: blaR1, blaR, BN1321_410015, BSZ10_11995, BTN44_15560, FA040_05105, GO941_06445, NCTC13131_00091, SAMEA2077334_00715, SAMEA2078260_01199, SAMEA2078588_01099, SAMEA2080344_00713, SAMEA2081063_00867, SAMEA2081470_00938, SAMEA70146418_00144, SAP084B_008, SAP086A_011 Production host: Lactobacillus delbrueckii subsp. lactis (bacteria) References: UniProt: Q00419 #2: Chemical | Has ligand of interest | N | |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
-Sample preparation
Component | Name: Dimeric complex of S. aureus BlaR1 F284A mutant in complex with ampicillin Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT |
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Molecular weight | Value: 0.142 MDa / Experimental value: NO |
Source (natural) | Organism: Staphylococcus aureus (bacteria) |
Source (recombinant) | Organism: Lactobacillus delbrueckii subsp. lactis (bacteria) |
Buffer solution | pH: 7.5 / Details: 20 mM HEPES, pH 7.5, 150 mM sodium chloride |
Specimen | Conc.: 0.5 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Cryogen name: ETHANE |
-Electron microscopy imaging
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: FEI TITAN KRIOS |
Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 3500 nm / Nominal defocus min: 1500 nm |
Image recording | Electron dose: 60 e/Å2 / Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) |
-Processing
EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||||||||||||||||||
Particle selection | Num. of particles selected: 5613933 | ||||||||||||||||||||||||||||||||||||||||
Symmetry | Point symmetry: C2 (2 fold cyclic) | ||||||||||||||||||||||||||||||||||||||||
3D reconstruction | Resolution: 4.6 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 216832 / Symmetry type: POINT |