2PU3
Structural adaptation of endonuclease I from the cold-adapted and halophilic bacterium Vibrio salmonicida
Summary for 2PU3
| Entry DOI | 10.2210/pdb2pu3/pdb |
| Related | 2g7e 2g7f |
| Descriptor | Endonuclease I, MAGNESIUM ION, CHLORIDE ION, ... (4 entities in total) |
| Functional Keywords | cold adaptation, salt adaptation, psychrophilic enzymes, endonuclease i, hydrolase |
| Biological source | Vibrio salmonicida |
| Total number of polymer chains | 1 |
| Total formula weight | 24679.11 |
| Authors | Altermark, B.,Helland, R.,Moe, E.,Willassen, N.P.,Smalas, A.O. (deposition date: 2007-05-08, release date: 2008-03-18, Last modification date: 2024-10-30) |
| Primary citation | Altermark, B.,Helland, R.,Moe, E.,Willassen, N.P.,Smalas, A.O. Structural adaptation of endonuclease I from the cold-adapted and halophilic bacterium Vibrio salmonicida. Acta Crystallogr.,Sect.D, 64:368-376, 2008 Cited by PubMed Abstract: The crystal structure of the periplasmic/extracellular endonuclease I from Vibrio salmonicida has been solved to 1.5 A resolution and, in comparison to the corresponding endonucleases from V. cholerae and V. vulnificus, serves as a model system for the investigation of the structural determinants involved in the temperature and NaCl adaptation of this enzyme class. The overall fold of the three enzymes is essentially similar, but the V. salmonicida endonuclease displays a significantly more positive surface potential than the other two enzymes owing to the presence of ten more Lys residues. However, if the optimum salt concentrations for the V. salmonicida and V. cholerae enzymes are taken into consideration in the electrostatic surface-potential calculation, the potentials of the two enzymes become surprisingly similar. The higher number of basic residues in the V. salmonicida protein is therefore likely to be a result, at least in part, of adaptation to the more saline habitat of V. salmonicida (seawater) than V. cholerae (brackish water). The hydrophobic core of all three enzymes is almost identical, but the V. salmonicida endonuclease has a slightly lower number of internal hydrogen bonds. This, together with repulsive forces between the basic residues on the protein surface of V. salmonicida endonuclease I and differences in the distribution of salt bridges, probably results in higher flexibility of regions of the V. salmonicida protein. This is likely to influence both the catalytic activity and the stability of the protein. PubMed: 18391403DOI: 10.1107/S0907444908000097 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.5 Å) |
Structure validation
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