2G8C

Atomic-resolution crystal structure of Borrelia burgdorferi OspA via surface entropy reduction

2G8C の概要

• エントリーDOI: 10.2210/pdb2g8c/pdb
• 分子名称: outer surface protein A, IMIDAZOLE, TETRAETHYLENE GLYCOL, ... (4 entities in total)
• 機能のキーワード: beta sheet, lipid binding protein
• 由来する生物種: Borrelia burgdorferi (Lyme disease spirochete)
• 細胞内の位置: Cell outer membrane; Lipid-anchor: P14013
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 26853.01

構造登録者

Makabe, K.,Tereshko, V.,Koide, S. (登録日: 2006-03-02, 公開日: 2006-08-08, 最終更新日: 2023-08-30)

主引用文献

Makabe, K.,Tereshko, V.,Gawlak, G.,Yan, S.,Koide, S.
Atomic-resolution crystal structure of Borrelia burgdorferi outer surface protein A via surface engineering.
Protein Sci., 15:1907-1914, 2006

PubMed Abstract: Outer surface protein A (OspA) from Borrelia burgdorferi has an unusual dumbbell-shaped structure in which two globular domains are connected with a "single-layer" beta-sheet (SLB). The protein is highly soluble, and it has been recalcitrant to crystallization. Only OspA complexes with Fab fragments have been successfully crystallized. OspA contains a large number of Lys and Glu residues, and these "high entropy" residues may disfavor crystal packing because some of them would need to be immobilized in forming a crystal lattice. We rationally designed a total of 13 surface mutations in which Lys and Glu residues were replaced with Ala or Ser. We successfully crystallized the mutant OspA without a bound Fab fragment and extended structure analysis to a 1.15 Angstroms resolution. The new high-resolution structure revealed a unique backbone hydration pattern of the SLB segment in which water molecules fill the "weak spots" on both faces of the antiparallel beta-sheet. These well-defined water molecules provide additional structural links between adjacent beta-strands, and thus they may be important for maintaining the rigidity of the SLB that inherently lacks tight packing afforded by a hydrophobic core. The structure also revealed new information on the side-chain dynamics and on a solvent-accessible cavity in the core of the C-terminal globular domain. This work demonstrates the utility of extensive surface mutation in crystallizing recalcitrant proteins and dramatically improving the resolution of crystal structures, and provides new insights into the stabilization mechanism of OspA.

PubMed: 16823038
DOI: 10.1110/ps.062246706

実験手法

X-RAY DIFFRACTION (1.15 Å)