1NQM

Structure of Savm-W120K, streptavidin mutant

1NQM の概要

• エントリーDOI: 10.2210/pdb1nqm/pdb
• 分子名称: Streptavidin, BIOTIN (3 entities in total)
• 機能のキーワード: avidin, streptavidin, biotin, monomer-monomer interaction, high affinity systems, unknown function
• 由来する生物種: Streptomyces avidinii
• 細胞内の位置: Secreted: P22629
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 57758.74

構造登録者

Pazy, Y.,Eisenberg-Domovich, Y.,Laitinen, O.H.,Kulomaa, M.S.,Bayer, E.A.,Wilchek, M.,Livnah, O. (登録日: 2003-01-22, 公開日: 2003-07-15, 最終更新日: 2024-02-14)

主引用文献

Pazy, Y.,Eisenberg-Domovich, Y.,Laitinen, O.H.,Kulomaa, M.S.,Bayer, E.A.,Wilchek, M.,Livnah, O.
Dimer-Tetramer Transition between Solution and Crystalline States of Streptavidin and Avidin Mutants.
J.Bacteriol., 185:4050-4056, 2003

PubMed Abstract: The biotin-binding tetrameric proteins, streptavidin from Streptomyces avidinii and chicken egg white avidin, are excellent models for the study of subunit-subunit interactions of a multimeric protein. Efforts are thus being made to prepare mutated forms of streptavidin and avidin, which would form monomers or dimers, in order to examine their effect on quaternary structure and assembly. In the present communication, we compared the crystal structures of binding site W-->K mutations in streptavidin and avidin. In solution, both mutant proteins are known to form dimers, but upon crystallization, both formed tetramers with the same parameters as the native proteins. All of the intersubunit bonds were conserved, except for the hydrophobic interaction between biotin and the tryptophan that was replaced by lysine. In the crystal structure, the binding site of the mutated apo-avidin contains 3 molecules of structured water instead of the 5 contained in the native protein. The lysine side chain extends in a direction opposite that of the native tryptophan, the void being partially filled by an adjacent lysine residue. Nevertheless, the binding-site conformation observed for the mutant tetramer is an artificial consequence of crystal packing that would not be maintained in the solution-phase dimer. It appears that the dimer-tetramer transition may be concentration dependent, and the interaction among subunits obeys the law of mass action.

PubMed: 12837778
DOI: 10.1128/JB.185.14.4050-4056.2003

実験手法

X-RAY DIFFRACTION (1.7 Å)