4N5X
Crystal structure of N-terminal calmodulin-like Calcium sensor of human mitochondrial ATP-Mg/Pi carrier SCaMC1
Summary for 4N5X
| Entry DOI | 10.2210/pdb4n5x/pdb |
| Descriptor | Calcium-binding mitochondrial carrier protein SCaMC-1, CALCIUM ION, DI(HYDROXYETHYL)ETHER, ... (4 entities in total) |
| Functional Keywords | calmodulin, calcium sensor, mitochondrial inner membrane, calcium-binding protein |
| Biological source | Homo sapiens (human) |
| Total number of polymer chains | 1 |
| Total formula weight | 23239.00 |
| Authors | Yang, Q.,Bruschweiler, S.,Chou, J. (deposition date: 2013-10-10, release date: 2013-12-18, Last modification date: 2023-09-20) |
| Primary citation | Yang, Q.,Bruschweiler, S.,Chou, J.J. A Self-Sequestered Calmodulin-like Ca(2+) Sensor of Mitochondrial SCaMC Carrier and Its Implication to Ca(2+)-Dependent ATP-Mg/Pi Transport. Structure, 22:209-217, 2014 Cited by 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. PubMed: 24332718DOI: 10.1016/j.str.2013.10.018 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.1 Å) |
Structure validation
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