2FGQ
High resolution X-ray structure of Omp32 in complex with malate
Summary for 2FGQ
| Entry DOI | 10.2210/pdb2fgq/pdb |
| Related | 2FGR |
| Descriptor | Outer membrane porin protein 32, octyl beta-D-glucopyranoside, CALCIUM ION, ... (6 entities in total) |
| Functional Keywords | porin, malate, outer membrane protein, membrane protein |
| Biological source | Delftia acidovorans |
| Cellular location | Cell outer membrane; Multi-pass membrane protein: P24305 |
| Total number of polymer chains | 1 |
| Total formula weight | 35586.43 |
| Authors | Zeth, K.,Engelhardt, H. (deposition date: 2005-12-22, release date: 2006-01-31, Last modification date: 2024-02-14) |
| Primary citation | Zachariae, U.,Kluhspies, T.,De, S.,Engelhardt, H.,Zeth, K. High resolution crystal structures and molecular dynamics studies reveal substrate binding in the porin omp32 J.Biol.Chem., 281:7413-7420, 2006 Cited by PubMed Abstract: The porin Omp32 is the major outer membrane protein of the bacterium Delftia acidovorans. The crystal structures of the strongly anion-selective porin alone and in complex with the substrate malate were solved at 1.5 and 1.45 A resolution, respectively, and revealed a malate-binding motif adjacent to the channel constriction zone. Binding is mediated by interaction with a cluster of two arginine residues and two threonines. This binding site is specific for Omp32 and reflects the physiological adaptation of the organism to organic acids. Structural studies are combined with a 7-ns unbiased molecular dynamics simulation of the trimeric channel in a model membrane. Molecular dynamics trajectories show how malate ions are efficiently captured from the surrounding bulk solution by the electrostatic potential of the channel, translocated to the binding site region, and immobilized in the constriction zone. In accordance with these results, conductance measurements with Omp32 inserted in planar lipid membranes revealed binding of malate. The anion-selective channel Omp32 is the first reported example of a porin with a 16-stranded beta-barrel and proven substrate specificity. This finding suggests a new view on the correlation of porin structure with substrate binding in specific channels. PubMed: 16434398DOI: 10.1074/jbc.M510939200 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.45 Å) |
Structure validation
Download full validation report
