Two cyclic C4 tetramers are stacked onto each other and are related by twofold symmetry axes creating the octameric structure with dihedral symmetry D4
温度: 281.15 K / pH: 7.5 詳細: The protein sample contained 10.3 mg/ml of hUGP, 50 mM HEPES pH 7.5, 5 mM MgCl2, 1 mM EDTA, 20% (w/v) sucrose and 4 mM UDP-Glc. 1 l of the hUGP UDP-Glc complex was mixed 1:1 with the ...詳細: The protein sample contained 10.3 mg/ml of hUGP, 50 mM HEPES pH 7.5, 5 mM MgCl2, 1 mM EDTA, 20% (w/v) sucrose and 4 mM UDP-Glc. 1 l of the hUGP UDP-Glc complex was mixed 1:1 with the reservoir solution containing 100 mM sodium acetate buffer pH 4.8, 520 mM zinc acetate, 6% (w/v) aminocaproic acid and 75 mM ammonium sulfate. , VAPOR DIFFUSION, SITTING DROP, temperature 281.15K
モノクロメーター: DIAMOND (111), GE(220) / プロトコル: SINGLE WAVELENGTH / 単色(M)・ラウエ(L): M / 散乱光タイプ: x-ray
放射波長
波長: 0.9334 Å / 相対比: 1
反射
解像度: 3.3→47.623 Å / Num. obs: 58213 / % possible obs: 99.7 % / Observed criterion σ(I): 2 / 冗長度: 12.3 % / Biso Wilson estimate: 96.27 Å2
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解析
ソフトウェア
名称
バージョン
分類
MxCuBE
データ収集
AMoRE
位相決定
PHENIX
(phenix.refine: 1.9_1692)
精密化
XDS
データ削減
SADABS
データスケーリング
精密化
構造決定の手法: 分子置換 / 解像度: 3.35→47.62 Å / SU ML: 0.41 / σ(F): 1.34 / 位相誤差: 24.49 / 立体化学のターゲット値: ML 詳細: Author stated the following: In the crystals of hUGP1-UDP-Glc complex the electron density for the substrate (UPG) as well as for some other parts of the structure was observed to be rather ...詳細: Author stated the following: In the crystals of hUGP1-UDP-Glc complex the electron density for the substrate (UPG) as well as for some other parts of the structure was observed to be rather weak. It may in part be explained by a certain degree of disorder within the unit cell, which is reflected in a high value of the Wilson B-factor (108.6 A**2) and a weaker electron density for the protein chain D. However, the partial electron density observed for the UPG ribose and the glucose moieties indicated that the substrate is present in the active site of protein chain A. To improve the quality of the electron density, especially in its weak regions, we performed a phase improvement procedure using the density modification (DM) methods in the following way. The DM was performed in a solvent flattening mode using Hendrickson-Lattman coefficients from the refined protein model with omitted substrate and ligands as an initial approximation. After several cycles of the DM, we observed a noticeable increase of the figure-of-merit (15% in a high-resolution shell). The resulting weighted structure factor and modified phases from DM procedure were used to calculate the composite 2Fo-Fc electron density which you can see on the figure attached to this message. The DM-improved ligand-omit map allowed to determine the binding mode of UPG unambiguously. In addition to the UPG, the DM map allowed to resolve several other weak density regions which were not clearly interpretable before. The described method of improvement of the weak electron density regions has been successfully applied to resolve the disordered protein regions in a publication: Fedorov R, Witte G, Urbanke C, Manstein DJ, Curth U. 3D structure of Thermus aquaticus single-stranded DNA-binding protein gives insight into the functioning of SSB proteins. (2006) Nucleic Acids Res 34, 6708-6717. and in a number of application notes of our group together with Bruker company. The considerable increase of the electron density quality and the value of figure-of-merit in the particular case of hUGP1.UDP-Glc complex structure can be explained by a high solvent content in the hUGP1.UDP-Glc complex crystals (Vs = 67.7%), which makes the phase improvement by solvent flattening procedure very efficient.
Rfactor
反射数
%反射
Rfree
0.247
2580
5.06 %
Rwork
0.199
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obs
0.202
50946
99.9 %
all
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49306
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溶媒の処理
減衰半径: 0.9 Å / VDWプローブ半径: 1.11 Å / 溶媒モデル: FLAT BULK SOLVENT MODEL