7DQV
Crystal structure of a CmABCB1 mutant
Summary for 7DQV
| Entry DOI | 10.2210/pdb7dqv/pdb |
| Descriptor | Probable ATP-dependent transporter ycf16, PHOSPHOAMINOPHOSPHONIC ACID-ADENYLATE ESTER, DECYL-BETA-D-MALTOPYRANOSIDE, ... (6 entities in total) |
| Functional Keywords | multidrug resistance abc transporter membrane protein, transport protein |
| Biological source | Cyanidioschyzon merolae (strain 10D) (Red alga) |
| Total number of polymer chains | 1 |
| Total formula weight | 68834.52 |
| Authors | Matsuoka, K.,Nakatsu, T.,Kato, H. (deposition date: 2020-12-24, release date: 2021-03-24, Last modification date: 2023-11-29) |
| Primary citation | Matsuoka, K.,Nakatsu, T.,Kato, H. The crystal structure of the CmABCB1 G132V mutant, which favors the outward-facing state, reveals the mechanism of the pivotal joint between TM1 and TM3. Protein Sci., 30:1064-1071, 2021 Cited by PubMed Abstract: CmABCB1 is a homologue of human P-glycoprotein, which extrudes various substrates by iterative cycles of conformational changes between the inward- and outward-facing states. Comparison of the inward- and outward-facing structures of CmABCB1 suggested that pivotal joints in the transmembrane domain regulate the tilt of transmembrane helices. Transmembrane helix 1 (TM1) forms a tight helix-helix contact with TM3 at the TM1-3 joint. Mutation of Gly132 to valine at the TM1-3 joint, G132V, caused a 10-fold increase in ATPase activity, but the mechanism underlying this change remains unclear. Here, we report a crystal structure of the outward-facing state of the CmABCB1 G132V mutant at a 2.15 Å resolution. We observed structural displacements between the outward-facing states of G132V and the previous one at the region around the TM1-3 joint, and a significant expansion at the extracellular gate. We hypothesize that steric hindrance caused by the Val substitution shifted the conformational equilibrium toward the outward-facing state, favoring the dimeric state of the nucleotide-binding domains and thereby increasing the ATPase activity of the G132V mutant. PubMed: 33683740DOI: 10.1002/pro.4058 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.15 Å) |
Structure validation
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