1CTR

DRUG BINDING BY CALMODULIN: CRYSTAL STRUCTURE OF A CALMODULIN-TRIFLUOPERAZINE COMPLEX

• PDB DOI:  https://doi.org/10.2210/pdb1CTR/pdb

• Classification: CALCIUM-BINDING PROTEIN
• Organism(s): Homo sapiens
• Mutation(s): No 


• Deposited: 1994-09-21 Released: 1994-12-20 
• Deposition Author(s): Cook, W.J., Walter, L.J., Walter, M.R.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.45 Å
• R-Value Work: 0.222 
• R-Value Observed: 0.222 

Literature

Drug binding by calmodulin: crystal structure of a calmodulin-trifluoperazine complex.

Cook, W.J., Walter, L.J., Walter, M.R.

(1994) Biochemistry 33: 15259-15265

• PubMed: 7803388 
• DOI: https://doi.org/10.1021/bi00255a006
• Primary Citation of Related Structures:  
  1CTR


• PubMed Abstract: 
  

The crystal structure of calmodulin (CaM) bound to trifluoperazine (TFP) has been determined and refined to a resolution of 2.45 A. Only one TFP is bound to CaM, but that is sufficient to cause distortion of the central alpha-helix and juxtaposition of the N- and C-terminal domains similar to that seen in CaM-polypeptide complexes. The drug makes extensive contacts with residues in the C-terminal domain of CaM but only a few contacts with one residue in the N-terminal domain. The structure suggests that substrate binding to the C-terminal domain is sufficient to cause the conformational changes in calmodulin that lead to activation of its targets.

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Organizational Affiliation: 

Department of Pathology, University of Alabama at Birmingham 35294.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 17.29 kDa 
• Atom Count: 1,140 
• Modelled Residue Count: 142 
• Deposited Residue Count: 148 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
CALMODULIN	A	148	Homo sapiens	Mutation(s): 0  Gene Names: CALM1, CALM, CAM, CAM1
UniProt & NIH Common Fund Data Resources
Find proteins for P0DP23 (Homo sapiens) Explore P0DP23  Go to UniProtKB:  P0DP23
PHAROS:  P0DP23

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
TFP	F [auth A]	10-[3-(4-METHYL-PIPERAZIN-1-YL)-PROPYL]-2-TRIFLUOROMETHYL-10H-PHENOTHIAZINE C21 H24 F3 N3 S ZEWQUBUPAILYHI-UHFFFAOYSA-N
CA	B [auth A], C [auth A], D [auth A], E [auth A]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Binding Affinity Annotations
ID	Source	Binding Affinity
TFP	BindingDB:  1CTR	Kd: min: 1000, max: 5000 (nM) from 3 assay(s)
	PDBBind:  1CTR	Kd: 1000 (nM) from 1 assay(s)

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.45 Å
• R-Value Work: 0.222 
• R-Value Observed: 0.222 
• Space Group: P 3₂ 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 41	α = 90
b = 41	β = 90
c = 178.9	γ = 120

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 1994-12-20 
Deposition Author(s): Cook, W.J., Walter, L.J., Walter, M.R.

Revision History  

• Version 1.0: 1994-12-20
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance