3NEP
1.55A resolution structure of malate dehydrogenase from Salinibacter ruber
Summary for 3NEP
| Entry DOI | 10.2210/pdb3nep/pdb |
| Descriptor | Malate dehydrogenase (2 entities in total) |
| Functional Keywords | malate dehydrogenase, halophile, molecular adpatation, nad, oxidoreductase, tricarboxylic acid cycle |
| Biological source | Salinibacter ruber |
| Total number of polymer chains | 1 |
| Total formula weight | 33286.59 |
| Authors | Coquelle, N.,Madern, D. (deposition date: 2010-06-09, release date: 2010-10-13, Last modification date: 2023-09-06) |
| Primary citation | Coquelle, N.,Talon, R.,Juers, D.H.,Girard, E.,Kahn, R.,Madern, D. Gradual adaptive changes of a protein facing high salt concentrations. J.Mol.Biol., 404:493-505, 2010 Cited by PubMed Abstract: Several experimental techniques were applied to unravel fine molecular details of protein adaptation to high salinity. We compared four homologous enzymes, which suggested a new halo-adaptive state in the process of molecular adaptation to high-salt conditions. Together with comparative functional studies, the structure of malate dehydrogenase from the eubacterium Salinibacter ruber shows that the enzyme shares characteristics of a halo-adapted archaea-bacterial enzyme and of non-halo-adapted enzymes from other eubacterial species. The S. ruber enzyme is active at the high physiological concentrations of KCl but, unlike typical halo-adapted enzymes, remains folded and active at low salt concentrations. Structural aspects of the protein, including acidic residues at the surface, solvent-exposed hydrophobic surface, and buried hydrophobic surface, place it between the typical halo-adapted and non-halo-adapted proteins. The enzyme lacks inter-subunit ion-binding sites often seen in halo-adapted enzymes. These observations permit us to suggest an evolutionary pathway that is highlighted by subtle trade-offs to achieve an optimal compromise among solubility, stability, and catalytic activity. PubMed: 20888835DOI: 10.1016/j.jmb.2010.09.055 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.551 Å) |
Structure validation
Download full validation report
