Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

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Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 35612.94 
• Atom Count: 2400 
• Residue Count: 309 
• Unique protein chains: 1

3TZM

TGF-beta Receptor type 1 in complex with SB431542

• DOI: 10.2210/pdb3TZM/pdb

• Classification: TRANSFERASE/TRANSFERASE INHIBITOR
• Organism(s): Homo sapiens
• Expression System: Spodoptera frugiperda


• Deposited: 2011-09-27 Released: 2012-05-23 
• Deposition Author(s): Ogunjimi, A.A., Zeqiraj, E., Ceccarelli, D.F., Sicheri, F.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.7 Å
• R-Value Free: 0.205 
• R-Value Work: 0.170 

Literature

Structural Basis for Specificity of TGFbeta Family Receptor Small Molecule Inhibitors

Ogunjimi, A.A., Zeqiraj, E., Ceccarelli, D.F., Sicheri, F., Wrana, J.L., David, L.

(2012) Cell Signal 24: 476-483

• PubMed: 21983015 
• DOI: 10.1016/j.cellsig.2011.09.027


• PubMed Abstract: 
  

Transforming growth factor-β (TGFβ) receptor kinase inhibitors have a great therapeutic potential. SB431542 is one of the mainly used kinase inhibitors of the TGFβ/Activin pathway receptors, but needs improvement of its EC(50) (EC(50)=1 μM) to be translated to clinical use. A key feature of SB431542 is that it specifically targets receptors from the TGFβ/Activin pathway but not the closely related receptors from the bone morphogenic proteins (BMP) pathway. To understand the mechanisms of this selectivity, we solved the crystal structure of the TGFβ type I receptor (TβRI) kinase domain in complex with SB431542. We mutated TβRI residues coordinating SB431542 to their counterparts in activin-receptor like kinase 2 (ALK2), a BMP receptor kinase, and tested the kinase activity of mutated TβRI. We discovered that a Ser280Thr mutation yielded a TβRI variant that was resistant to SB431542 inhibition. Furthermore, the corresponding Thr283Ser mutation in ALK2 yielded a BMP receptor sensitive to SB431542. This demonstrated that Ser280 is the key determinant of selectivity for SB431542. This work provides a framework for optimising the SB431542 scaffold to more potent and selective inhibitors of the TGFβ/Activin pathway.

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Organizational Affiliation: 

Center for Systems Biology, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
TGF-beta receptor type-1	A	309	Homo sapiens	Mutation(s): 0  Gene Names: TGFBR1 (ALK5, SKR4) EC: 2.7.11.30
Find proteins for P36897 (Homo sapiens) Go to Gene View: TGFBR1 Go to UniProtKB:  P36897

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
085	A	4-[5-(1,3-benzodioxol-5-yl)-4-(pyridin-2-yl)-1H-imidazol-2-yl]benzamide SB431542 C22 H16 N4 O3 FHYUGAJXYORMHI-UHFFFAOYSA-N

External Ligand Annotations
ID	Binding Affinity (Sequence Identity %)
085	Kd: 170 - 190 nM (100) BINDINGDB
085	Ki: 17 nM (100) BINDINGDB
085	IC50: 66 - 1542 nM (100) BINDINGDB
085	EC50: 172 nM (100) BINDINGDB
85	Ki: 17 nM PDBBIND

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.7 Å
• R-Value Free: 0.205 
• R-Value Work: 0.170 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length (Å)	Angle (°)
a = 41.771	α = 90.00
b = 77.726	β = 90.00
c = 90.070	γ = 90.00

Software Package:

Software Name	Purpose
HKL-2000	data reduction
ADSC	data collection
MOLREP	phasing
SCALEPACK	data scaling
REFMAC	refinement

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2011-09-27 
• Released Date: 2012-05-23 
• Deposition Author(s): Ogunjimi, A.A., Zeqiraj, E., Ceccarelli, D.F., Sicheri, F.

Revision History 

• Version 1.0: 2012-05-23
  Type: Initial release