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4GD9

Circular Permuted Streptavidin N49/G48

4GD9 の概要
エントリーDOI10.2210/pdb4gd9/pdb
関連するPDBエントリー1SWF
分子名称Streptavidin, BIOTIN, SULFATE ION, ... (4 entities in total)
機能のキーワードbiotin-binding protein, biotin, circular permutation
由来する生物種Streptomyces avidinii
詳細
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55852.45
構造登録者
Le Trong, I.,Chu, V.,Xing, Y.,Lybrand, T.P.,Stayton, P.S.,Stenkamp, R.E. (登録日: 2012-07-31, 公開日: 2013-06-05, 最終更新日: 2023-09-13)
主引用文献Le Trong, I.,Chu, V.,Xing, Y.,Lybrand, T.P.,Stayton, P.S.,Stenkamp, R.E.
Structural consequences of cutting a binding loop: two circularly permuted variants of streptavidin.
Acta Crystallogr.,Sect.D, 69:968-977, 2013
Cited by
PubMed Abstract: Circular permutation of streptavidin was carried out in order to investigate the role of a main-chain amide in stabilizing the high-affinity complex of the protein and biotin. Mutant proteins CP49/48 and CP50/49 were constructed to place new N-termini at residues 49 and 50 in a flexible loop involved in stabilizing the biotin complex. Crystal structures of the two mutants show that half of each loop closes over the binding site, as observed in wild-type streptavidin, while the other half adopts the open conformation found in the unliganded state. The structures are consistent with kinetic and thermodynamic data and indicate that the loop plays a role in enthalpic stabilization of the bound state via the Asn49 amide-biotin hydrogen bond. In wild-type streptavidin, the entropic penalties of immobilizing a flexible portion of the protein to enhance binding are kept to a manageable level by using a contiguous loop of medium length (six residues) which is already constrained by its anchorage to strands of the β-barrel protein. A molecular-dynamics simulation for CP50/49 shows that cleavage of the binding loop results in increased structural fluctuations for Ser45 and that these fluctuations destabilize the streptavidin-biotin complex.
PubMed: 23695241
DOI: 10.1107/S0907444913003855
主引用文献が同じPDBエントリー
実験手法
X-RAY DIFFRACTION (1.5 Å)
構造検証レポート
Validation report summary of 4gd9
検証レポート(詳細版)ダウンロードをダウンロード

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件を2024-12-25に公開中

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