Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

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

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

Macromolecule Content

• Total Structure Weight: 23.24 kDa 
• Atom Count: 1390 
• Modelled Residue Count: 155 
• Deposited Residue Count: 199 
• Unique protein chains: 1

4N5X

Crystal structure of N-terminal calmodulin-like Calcium sensor of human mitochondrial ATP-Mg/Pi carrier SCaMC1

• PDB DOI: 10.2210/pdb4N5X/pdb

• Classification: CALCIUM-BINDING PROTEIN
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2013-10-10 Released: 2013-12-18 
• Deposition Author(s): Yang, Q., Bruschweiler, S., Chou, J.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.10 Å
• R-Value Free: 0.225 
• R-Value Work: 0.177 
• R-Value Observed: 0.182 

Literature

A Self-Sequestered Calmodulin-like Ca(2+) Sensor of Mitochondrial SCaMC Carrier and Its Implication to Ca(2+)-Dependent ATP-Mg/Pi Transport.

Yang, Q., Bruschweiler, S., Chou, J.J.

(2014) Structure 22: 209-217

• PubMed: 24332718 
• DOI: 10.1016/j.str.2013.10.018
• Primary Citation of Related Structures:  
  4N5X


• PubMed Abstract: 
  

The mitochondrial carriers play essential roles in energy metabolism. The short Ca²⁺-binding mitochondrial carrier (SCaMC) transports ATP-Mg in exchange for Pi and is important for activities that depend on adenine nucleotides. SCaMC adopts, in addition to the transmembrane domain (TMD) that transports solutes, an extramembrane N-terminal domain (NTD) that regulates solute transport in a Ca²⁺-dependent manner. Crystal structure of the Ca²⁺-bound NTD reveals a compact architecture in which the functional EF hands are sequestered by an endogenous helical segment. Nuclear magnetic resonance (NMR) relaxation rates indicated that removal of Ca²⁺ from NTD results in a major conformational switch from the rigid and compact Ca²⁺-bound state to the dynamic and loose apo state. Finally, we showed using surface plasmon resonance and NMR titration experiments that free apo NTDs could specifically interact with liposome-incorporated TMD, but that Ca²⁺ binding drastically weakened the interaction. Our results together provide a molecular explanation for Ca²⁺-dependent ATP-Mg flux in mitochondria.

---

Organizational Affiliation: 

Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA. Electronic address: [e-mail].

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Calcium-binding mitochondrial carrier protein SCaMC-1	A	199	Homo sapiens	Mutation(s): 1  Gene Names: SLC25A24, APC1, MCSC1, SCAMC1
UniProt & NIH Common Fund Data Resources
Find proteins for Q6NUK1 (Homo sapiens) Explore Q6NUK1  Go to UniProtKB:  Q6NUK1
PHAROS:  Q6NUK1

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
PEG	G [auth A]	DI(HYDROXYETHYL)ETHER C4 H10 O3 MTHSVFCYNBDYFN-UHFFFAOYSA-N
CA	B [auth A], C [auth A], D [auth A], E [auth A], F [auth A]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.10 Å
• R-Value Free: 0.225 
• R-Value Work: 0.177 
• R-Value Observed: 0.182 
• Space Group: P 3₁ 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 51.21	α = 90
b = 51.21	β = 90
c = 112.153	γ = 120

Software Package:

Software Name	Purpose
HKL-2000	data collection
PHASER	phasing
PHENIX	refinement
HKL-2000	data reduction
HKL-2000	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2013-10-10 
• Released Date: 2013-12-18 
Deposition Author(s): Yang, Q., Bruschweiler, S., Chou, J.

Revision History  

• Version 1.0: 2013-12-18
  Type: Initial release
  
• Version 1.1: 2014-02-26
  Changes: Database references
• Version 1.2: 2018-06-13
  Changes: Data collection