7MLT | pdb_00007mlt

Crystal structure of ricin A chain in complex with 5-(2-ethylphenyl)thiophene-2-carboxylic acid


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 
    0.203 (Depositor), 0.209 (DCC) 
  • R-Value Work: 
    0.177 (Depositor), 0.187 (DCC) 
  • R-Value Observed: 
    0.178 (Depositor) 

Starting Model: experimental
View more details

wwPDB Validation 3D Report Full Report

Validation slider image for 7MLT

Ligand Structure Quality Assessment 


This is version 1.1 of the entry. See complete history

Literature

Synthesis and Structural Characterization of Ricin Inhibitors Targeting Ribosome Binding Using Fragment-Based Methods and Structure-Based Design.

Li, X.P.Harijan, R.K.Cao, B.Kahn, J.N.Pierce, M.Tsymbal, A.M.Roberge, J.Y.Augeri, D.Tumer, N.E.

(2021) J Med Chem 64: 15334-15348

  • DOI: https://doi.org/10.1021/acs.jmedchem.1c01370
  • Primary Citation Related Structures: 
    7MLN, 7MLO, 7MLP, 7MLT

  • PubMed Abstract: 

    Ricin toxin A subunit (RTA) is the catalytic subunit of ricin, which depurinates an adenine from the sarcin/ricin loop in eukaryotic ribosomes. There are no approved inhibitors against ricin. We used a new strategy to disrupt RTA-ribosome interactions by fragment screening using surface plasmon resonance. Here, using a structure-guided approach, we improved the affinity and inhibitory activity of small-molecular-weight lead compounds and obtained improved compounds with over an order of magnitude higher efficiency. Four advanced compounds were characterized by X-ray crystallography. They bind at the RTA-ribosome binding site as the original compound but in a distinctive manner. These inhibitors bind remotely from the catalytic site and cause local conformational changes with no alteration of the catalytic site geometry. Yet they inhibit depurination by ricin holotoxin and inhibit the cytotoxicity of ricin in mammalian cells. They are the first agents that protect against ricin holotoxin by acting directly on RTA.


  • Organizational Affiliation
    • Department of Plant Biology, Rutgers, The State University of New Jersey, 59 Dudley Road, New Brunswick, New Jersey 08901, United States.

Macromolecule Content 

  • Total Structure Weight: 31.52 kDa 
  • Atom Count: 2,408 
  • Modeled Residue Count: 256 
  • Deposited Residue Count: 268 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Ricin268Ricinus communisMutation(s): 0 
EC: 3.2.2.22
UniProt
Find proteins for P02879 (Ricinus communis)
Explore P02879 
Go to UniProtKB:  P02879
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP02879
Sequence Annotations
Expand
Reference Sequence

Small Molecules

Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
ZJD
(Subject of Investigation/LOI)

Query on ZJD



Download:Ideal Coordinates CCD File
W [auth A]5-(2-ethylphenyl)thiophene-2-carboxylic acid
C13 H12 O2 S
MVIOXXJJRFAADN-UHFFFAOYSA-N
EDO

Query on EDO



Download:Ideal Coordinates CCD File
E [auth A]
F [auth A]
G [auth A]
H [auth A]
I [auth A]
E [auth A],
F [auth A],
G [auth A],
H [auth A],
I [auth A],
J [auth A],
K [auth A],
L [auth A],
M [auth A],
N [auth A],
O [auth A],
P [auth A],
Q [auth A],
R [auth A],
S [auth A],
T [auth A],
U [auth A],
V [auth A]
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
CL

Query on CL



Download:Ideal Coordinates CCD File
B [auth A],
C [auth A],
D [auth A]
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free:  0.203 (Depositor), 0.209 (DCC) 
  • R-Value Work:  0.177 (Depositor), 0.187 (DCC) 
  • R-Value Observed: 0.178 (Depositor) 
Space Group: P 63 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 168.618α = 90
b = 168.618β = 90
c = 54.949γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
PDB_EXTRACTdata extraction
MOSFLMdata reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)United StatesAI072425

Revision History  (Full details and data files)

  • Version 1.0: 2022-02-09
    Type: Initial release
  • Version 1.1: 2023-10-18
    Changes: Data collection, Refinement description