8GAJ | pdb_00008gaj

Crystal Structure of E. coli LptA in complex with Podisus maculiventris Thanatin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.43 Å
  • R-Value Free: 
    0.242 (Depositor), 0.241 (DCC) 
  • R-Value Work: 
    0.194 (Depositor), 0.194 (DCC) 
  • R-Value Observed: 
    0.196 (Depositor) 

Starting Model: in silico
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wwPDB Validation 3D Report Full Report

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Literature

Discovery, characterization, and redesign of potent antimicrobial thanatin orthologs from Chinavia ubica and Murgantia histrionica targeting E. coli LptA.

Huynh, K.Kibrom, A.Donald, B.R.Zhou, P.

(2023) J Struct Biol X 8: 100091-100091

  • DOI: https://doi.org/10.1016/j.yjsbx.2023.100091
  • Primary Citation Related Structures: 
    8GAJ, 8GAK, 8GAL

  • PubMed Abstract: 

    Podisus maculiventris thanatin has been reported as a potent antimicrobial peptide with antibacterial and antifungal activity. Its antibiotic activity has been most thoroughly characterized against E. coli and shown to interfere with multiple pathways, such as the lipopolysaccharide transport (LPT) pathway comprised of seven different Lpt proteins. Thanatin binds to E. coli LptA and LptD, thus disrupting the LPT complex formation and inhibiting cell wall synthesis and microbial growth. Here, we performed a genomic database search to uncover novel thanatin orthologs, characterized their binding to E. coli LptA using bio-layer interferometry, and assessed their antimicrobial activity against E. coli . We found that thanatins from Chinavia ubica and Murgantia histrionica bound tighter (by 3.6- and 2.2-fold respectively) to LptA and exhibited more potent antibiotic activity (by 2.1- and 2.8-fold respectively) than the canonical thanatin from P. maculiventris . We crystallized and determined the LptA-bound complex structures of thanatins from C. ubica (1.90 Å resolution), M. histrionica (1.80 Å resolution), and P. maculiventris (2.43 Å resolution) to better understand their mechanism of action. Our structural analysis revealed that residues A10 and I21 in C. ubica and M. histrionica thanatin are important for improving the binding interface with LptA, thus overall improving the potency of thanatin against E. coli . We also designed a stapled variant of thanatin that removes the need for a disulfide bond but retains the ability to bind LptA and antibiotic activity. Our discovery presents a library of novel thanatin sequences to serve as starting scaffolds for designing more potent antimicrobial therapeutics.


  • Organizational Affiliation
    • Department of Biochemistry, Duke University School of Medicine, Durham, NC, United States.

Macromolecule Content 

  • Total Structure Weight: 33.96 kDa 
  • Atom Count: 2,406 
  • Modeled Residue Count: 292 
  • Deposited Residue Count: 306 
  • Unique protein chains: 2

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Lipopolysaccharide export system protein LptA
A, C
132Escherichia coliMutation(s): 0 
Gene Names: lptA
UniProt
Find proteins for P0ADV1 (Escherichia coli (strain K12))
Explore P0ADV1 
Go to UniProtKB:  P0ADV1
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0ADV1
Sequence Annotations
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Reference Sequence
Find similar proteins by:  Sequence   |   3D Structure  
Entity ID: 2
MoleculeChains  Sequence LengthOrganismDetailsImage
Thanatin
B, D
21Podisus maculiventrisMutation(s): 0 
UniProt
Find proteins for P55788 (Podisus maculiventris)
Explore P55788 
Go to UniProtKB:  P55788
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP55788
Sequence Annotations
Expand
Reference Sequence

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.43 Å
  • R-Value Free:  0.242 (Depositor), 0.241 (DCC) 
  • R-Value Work:  0.194 (Depositor), 0.194 (DCC) 
  • R-Value Observed: 0.196 (Depositor) 
Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 44.95α = 90
b = 61.83β = 90
c = 150.33γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XSCALEdata scaling
PHASERphasing

Structure Validation

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Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)United States--
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United States--

Revision History  (Full details and data files)

  • Version 1.0: 2023-07-19
    Type: Initial release
  • Version 1.1: 2024-10-16
    Changes: Data collection, Structure summary