構造決定の手法: 分子置換 / 解像度: 3.41→41.27 Å / Cor.coef. Fo:Fc: 0.922 / Cor.coef. Fo:Fc free: 0.86 / SU B: 15.94 / SU ML: 0.243 / TLS residual ADP flag: LIKELY RESIDUAL / 交差検証法: THROUGHOUT / ESU R: 1.115 / ESU R Free: 0.426 / 立体化学のターゲット値: MAXIMUM LIKELIHOOD 詳細: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS. Many of the basic and novel features of the structure of the cyanobacterial b6f complex reported now in entries 2E74 (native), 2E75 (with ...詳細: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS. Many of the basic and novel features of the structure of the cyanobacterial b6f complex reported now in entries 2E74 (native), 2E75 (with quinone analogue inhibitor NQNO), and 2E76 (with quinone analogue inhibitor TDS) were seen in the original 3.0 A structure that was refined in space group P61 (Science, 302:1009-, 2003; pdb entry, 1VF5). This structure was thought to be a co-complex with tridecyl-stigmatellin (TDS). This inference was based on: (i) the highest resolution of 3 A was obtained in the TDS co-crystals, the native structure having a poorer resolution; (ii) electron density outside the portal on the p-side of the quinone exchange cavity resembled the TDS ring. Because of the poorer resolution of the native complex at that time, it was not possible to check for the presence of this density in the native structure. Entry 2E74 reports a 3.0 A native structure obtained in the presence of Cd2+, which shows the density previously attributed to the TDS ring. The correct p-side position of TDS, reported in 2E76, and in agreement with its location in the C. reinhardtii b6f structure (entry 1Q90) was obtained when the DOPC lipid that was added to accelerate crystallization (PNAS,100: 5160-5163) was added after TDS. 2E76 also shows a unique second binding site for TDS on the n-side of the complex, close to the position of an axial ligand of heme cn. Entry 2E75 shows that the inhibitor NQNO occupies a similar n-side binding site. This site that is common to the binding of the two quinone analogue inhibitors implies that it is also the n-side binding site of plastoquinone. 2E74,2E75, and 2E76 were refined in space group P6122.
Rfactor
反射数
%反射
Selection details
Rfree
0.25563
1852
5 %
RANDOM
Rwork
0.18473
-
-
-
obs
0.18822
35129
99.68 %
-
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: 1.4 Å / 溶媒モデル: MASK