ジャーナル: PLoS Pathog / 年: 2015 タイトル: Dimerization-Induced Allosteric Changes of the Oxyanion-Hole Loop Activate the Pseudorabies Virus Assemblin pUL26N, a Herpesvirus Serine Protease. 著者: Martin Zühlsdorf / Sebastiaan Werten / Barbara G Klupp / Gottfried J Palm / Thomas C Mettenleiter / Winfried Hinrichs / 要旨: Herpesviruses encode a characteristic serine protease with a unique fold and an active site that comprises the unusual triad Ser-His-His. The protease is essential for viral replication and as such ...Herpesviruses encode a characteristic serine protease with a unique fold and an active site that comprises the unusual triad Ser-His-His. The protease is essential for viral replication and as such constitutes a promising drug target. In solution, a dynamic equilibrium exists between an inactive monomeric and an active dimeric form of the enzyme, which is believed to play a key regulatory role in the orchestration of proteolysis and capsid assembly. Currently available crystal structures of herpesvirus proteases correspond either to the dimeric state or to complexes with peptide mimetics that alter the dimerization interface. In contrast, the structure of the native monomeric state has remained elusive. Here, we present the three-dimensional structures of native monomeric, active dimeric, and diisopropyl fluorophosphate-inhibited dimeric protease derived from pseudorabies virus, an alphaherpesvirus of swine. These structures, solved by X-ray crystallography to respective resolutions of 2.05, 2.10 and 2.03 Å, allow a direct comparison of the main conformational states of the protease. In the dimeric form, a functional oxyanion hole is formed by a loop of 10 amino-acid residues encompassing two consecutive arginine residues (Arg136 and Arg137); both are strictly conserved throughout the herpesviruses. In the monomeric form, the top of the loop is shifted by approximately 11 Å, resulting in a complete disruption of the oxyanion hole and loss of activity. The dimerization-induced allosteric changes described here form the physical basis for the concentration-dependent activation of the protease, which is essential for proper virus replication. Small-angle X-ray scattering experiments confirmed a concentration-dependent equilibrium of monomeric and dimeric protease in solution.
解像度: 2.05→78.81 Å / Cor.coef. Fo:Fc: 0.965 / Cor.coef. Fo:Fc free: 0.94 / SU B: 9.117 / SU ML: 0.123 / 交差検証法: THROUGHOUT / ESU R: 0.164 / ESU R Free: 0.156 / 立体化学のターゲット値: MAXIMUM LIKELIHOOD 詳細: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS. U VALUES WITH TLS ADDED. RESIDUES 15,20,46,79,189 AND 198 OF CHAIN A AND RESIDUES 19,46,156,165,172,185,189,192,193,199,202, ,206 AND 218 OF ...詳細: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS. U VALUES WITH TLS ADDED. RESIDUES 15,20,46,79,189 AND 198 OF CHAIN A AND RESIDUES 19,46,156,165,172,185,189,192,193,199,202, ,206 AND 218 OF CHAIN B MODELED AS ALA AND RESIDUE 44 FROM CHAIN A SHORTENED DUE TO INSUFFICIENT ELECTRON DENSITY, TAG WITH THROMBIN -LINKER OF BOTH CHAINS AND RESIDUES 16- -19 OF CHAIN A AND RESIDUES 14-18,194-196 AND 224 OF CHAIN B ARE DISORDERED
Rfactor
反射数
%反射
Selection details
Rfree
0.22704
1649
4.9 %
RANDOM
Rwork
0.17889
-
-
-
obs
0.18122
31876
99.57 %
-
溶媒の処理
イオンプローブ半径: 0.8 Å / 減衰半径: 0.8 Å / VDWプローブ半径: 1.2 Å / 溶媒モデル: MASK