2PU3

Structural adaptation of endonuclease I from the cold-adapted and halophilic bacterium Vibrio salmonicida

2PU3 の概要

• エントリーDOI: 10.2210/pdb2pu3/pdb
• 関連するPDBエントリー: 2g7e 2g7f
• 分子名称: Endonuclease I, MAGNESIUM ION, CHLORIDE ION, ... (4 entities in total)
• 機能のキーワード: cold adaptation, salt adaptation, psychrophilic enzymes, endonuclease i, hydrolase
• 由来する生物種: Vibrio salmonicida
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 24679.11

構造登録者

Altermark, B.,Helland, R.,Moe, E.,Willassen, N.P.,Smalas, A.O. (登録日: 2007-05-08, 公開日: 2008-03-18, 最終更新日: 2024-10-30)

主引用文献

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

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: 18391403
DOI: 10.1107/S0907444908000097

実験手法

X-RAY DIFFRACTION (1.5 Å)