6E1K

Structure of AtTPC1(DDE) reconstituted in saposin A with cat06 Fab


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.30 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural basis for activation of voltage sensor domains in an ion channel TPC1.

Kintzer, A.F.Green, E.M.Dominik, P.K.Bridges, M.Armache, J.P.Deneka, D.Kim, S.S.Hubbell, W.Kossiakoff, A.A.Cheng, Y.Stroud, R.M.

(2018) Proc Natl Acad Sci U S A 115: E9095-E9104

  • DOI: https://doi.org/10.1073/pnas.1805651115
  • Primary Citation of Related Structures:  
    6CX0, 6E1K, 6E1M, 6E1N, 6E1P

  • PubMed Abstract: 

    Voltage-sensing domains (VSDs) couple changes in transmembrane electrical potential to conformational changes that regulate ion conductance through a central channel. Positively charged amino acids inside each sensor cooperatively respond to changes in voltage. Our previous structure of a TPC1 channel captured an example of a resting-state VSD in an intact ion channel. To generate an activated-state VSD in the same channel we removed the luminal inhibitory Ca 2+ -binding site (Ca i 2+ ), which shifts voltage-dependent opening to more negative voltage and activation at 0 mV. Cryo-EM reveals two coexisting structures of the VSD, an intermediate state 1 that partially closes access to the cytoplasmic side but remains occluded on the luminal side and an intermediate activated state 2 in which the cytoplasmic solvent access to the gating charges closes, while luminal access partially opens. Activation can be thought of as moving a hydrophobic insulating region of the VSD from the external side to an alternate grouping on the internal side. This effectively moves the gating charges from the inside potential to that of the outside. Activation also requires binding of Ca 2+ to a cytoplasmic site (Ca a 2+ ). An X-ray structure with Ca a 2+ removed and a near-atomic resolution cryo-EM structure with Ca i 2+ removed define how dramatic conformational changes in the cytoplasmic domains may communicate with the VSD during activation. Together four structures provide a basis for understanding the voltage-dependent transition from resting to activated state, the tuning of VSD by thermodynamic stability, and this channel's requirement of cytoplasmic Ca 2+ ions for activation.


  • Organizational Affiliation

    Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Two pore calcium channel protein 1
A, B
727Arabidopsis thalianaMutation(s): 0 
Gene Names: TPC1CCH1FOU2At4g03560F9H3.19T5L23.5
Membrane Entity: Yes 
UniProt
Find proteins for Q94KI8 (Arabidopsis thaliana)
Explore Q94KI8 
Go to UniProtKB:  Q94KI8
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ94KI8
Sequence Annotations
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  • Reference Sequence
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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
cat06 light chain
C, E
214Homo sapiensMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
cat06 heavy chain
D, F
231Homo sapiensMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
PLM
Query on PLM

Download Ideal Coordinates CCD File 
AA [auth B]
K [auth A]
L [auth A]
M [auth A]
N [auth A]
AA [auth B],
K [auth A],
L [auth A],
M [auth A],
N [auth A],
O [auth A],
P [auth A],
Q [auth A],
R [auth A],
V [auth B],
W [auth B],
X [auth B],
Y [auth B],
Z [auth B]
PALMITIC ACID
C16 H32 O2
IPCSVZSSVZVIGE-UHFFFAOYSA-N
CA
Query on CA

Download Ideal Coordinates CCD File 
G [auth A]
H [auth A]
I [auth A]
J [auth A]
S [auth B]
G [auth A],
H [auth A],
I [auth A],
J [auth A],
S [auth B],
T [auth B],
U [auth B]
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
Modified Residues  2 Unique
IDChains TypeFormula2D DiagramParent
SEP
Query on SEP
A, B
L-PEPTIDE LINKINGC3 H8 N O6 PSER
TPO
Query on TPO
A, B
L-PEPTIDE LINKINGC4 H10 N O6 PTHR
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.30 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
MODEL REFINEMENTPHENIX1.13-2998
RECONSTRUCTIONRELION2.1.0

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesR01GM24485
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesR01GM098672

Revision History  (Full details and data files)

  • Version 1.0: 2018-09-19
    Type: Initial release
  • Version 1.1: 2018-10-03
    Changes: Data collection, Database references
  • Version 1.2: 2019-12-18
    Changes: Author supporting evidence, Other