4RJD

TFP bound in alternate orientations to calcium-saturated Calmodulin C-Domains


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.177 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Opposing orientations of the anti-psychotic drug trifluoperazine selected by alternate conformations of M144 in calmodulin.

Feldkamp, M.D.Gakhar, L.Pandey, N.Shea, M.A.

(2015) Proteins 83: 989-996

  • DOI: 10.1002/prot.24781

  • PubMed Abstract: 
  • The anti-psychotic drug trifluoperazine (TFP) is an antagonist observed to bind to calcium-saturated calmodulin ((Ca(2+) )4 -CaM) at ratios of 1:1 (1CTR), 2:1 (1A29), and 4:1 (1LIN). Each structure contains one TFP bound in the hydrophobic cleft of t ...

    The anti-psychotic drug trifluoperazine (TFP) is an antagonist observed to bind to calcium-saturated calmodulin ((Ca(2+) )4 -CaM) at ratios of 1:1 (1CTR), 2:1 (1A29), and 4:1 (1LIN). Each structure contains one TFP bound in the hydrophobic cleft of the C-domain of CaM. However, the orientation of the trifluoromethyl (CF3 ) moiety differs among them: it is buried in the C-domain cleft of 1A29 and 1LIN, but protrudes from 1CTR. We report a 2.0 Å resolution crystallographic structure (4RJD) of TFP bound to the (Ca(2+) )-saturated C-domain of CaM (CaMC ). The asymmetric unit contains two molecules of (Ca(2+) )2 -CaMC . Chain backbones were nearly identical, but the orientation of TFP in the cleft of Chain A matched 1A29/1LIN, while TFP bound to Chain B matched 1CTR. This was accommodated by a flip of the M144 sidechain and small changes in sidechains of M109 and M145. Docking simulations suggested that the rotamer conformation of M144 determined the orientation of TFP within the cleft of (Ca(2+) )2 -CaMC . Chains A and B show that the open cleft of (Ca(2+) )2 -CaMC is promiscuous in accepting TFP in reversed directions under the same crystallization conditions. Observing multiple orientations of an antagonist bound to a single protein highlights the challenge of designing highly specific pharmaceuticals, and may have importance for QSAR of other CF3 -containing drugs such as fluoxetine (anti-depressant) or efavirenz (reverse transcriptase inhibitor). This study emphasizes that a single structure of a complex represents an energetically accessible state, but does not necessarily show the full range of energetically equivalent states.


    Organizational Affiliation

    Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, 52242-1109.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Calmodulin
A, B
66Rattus norvegicusMutation(s): 0 
Gene Names: Calm2 (Cam2, Camb, CaMII)
Find proteins for P0DP30 (Rattus norvegicus)
Go to UniProtKB:  P0DP30
Small Molecules
Ligands 6 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SCN
Query on SCN

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B
THIOCYANATE ION
C N S
ZMZDMBWJUHKJPS-UHFFFAOYSA-M
 Ligand Interaction
CL
Query on CL

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A, B
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
CA
Query on CA

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A, B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
TFP
Query on TFP

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A, B
10-[3-(4-METHYL-PIPERAZIN-1-YL)-PROPYL]-2-TRIFLUOROMETHYL-10H-PHENOTHIAZINE
C21 H24 F3 N3 S
ZEWQUBUPAILYHI-UHFFFAOYSA-N
 Ligand Interaction
OXL
Query on OXL

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A
OXALATE ION
C2 O4
MUBZPKHOEPUJKR-UHFFFAOYSA-L
 Ligand Interaction
1PE
Query on 1PE

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A
PENTAETHYLENE GLYCOL
PEG400
C10 H22 O6
JLFNLZLINWHATN-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
TFPKd: 1000 - 5000 nM (100) BINDINGDB
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.177 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 24.606α = 90.00
b = 85.637β = 93.00
c = 35.341γ = 90.00
Software Package:
Software NamePurpose
d*TREKdata scaling
Blu-Icedata collection
PHENIXrefinement
PHASERphasing
d*TREKdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-08-26
    Type: Initial release
  • Version 1.1: 2017-11-22
    Type: Refinement description