STRUCTURE OF UBIQUITIN REFINED AT 1.8 A RESOLUTION
STRUCTURE OF UBIQUITIN REFINED AT 1.8 A RESOLUTION
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DOI：
10.1016/0022-2836(87)90679-6
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发表时间：
1987-04-05
影响因子：
5.6
通讯作者：
COOK, WJ
中科院分区：
文献类型：
--
作者：
VIJAYKUMAR, S;BUGG, CE;COOK, WJ
人红细胞泛蛋白的晶体结构已在1.8埃处得到改进。分辨率使用约束最小二乘程序。最终模型的晶体学R因子为0.176。分子中的键长和键角具有与理想值0.016埃的均方根偏差。和1.5 °，分别在最终模型中，每个泛素分子总共包含58个水分子。分子中的最后四个残基似乎具有部分占据或大的热运动。泛素的整体结构是非常紧凑和紧密的氢键;大约87%的多肽链参与氢键二级结构。突出的二级结构特征包括α-β的三个半圈。螺旋、310-螺旋的短片段、混合的β-一个包含五股和七个反向转弯的床单。在β-聚乙烯之间形成有明显的疏水核。片和α-螺旋。该分子具有许多不寻常的二级结构特征，包括平行的G1 β-凸起，两个反向Asx转弯，以及涉及两个螺旋和两个反向转弯的对称氢键区域。
The crystal structure of human erythrocytic ubiquitin has been refined at 1.8 .ANG. resolution using a restrained least-squares procedure. The crystallographic R-factor for the final model is 0.176. Bond lengths and bond angles in the molecule have root-mean-square deviations from ideal values of 0.016 .ANG. and 1.5.degree., respectively. A total of 58 water molecules per molecule of ubiquitin are included in the final model. The last four residues in the molecule appear to have partial occupancy or large thermal motion. The overall structure of ubiquitin is extremely compact and tightly hydrogen-bonded; approximately 87% of the polypeptide chain is involved in hydrogen-bonded secondary structure. Prominent secondary structural features include three and one-half turns of .alpha.-helix, a short piece of 310-helix, a mixed .beta.-sheet that contains five strands, and seven reverse turns. There is a marked hydrophobic core formed between the .beta.-sheet and .alpha.-helix. The molecule features a number of unusual secondary structural features, including a parallel G1 .beta.-bulge, two reverse Asx turns, and a symmetrical hydrogen-bonding region that involves the two helices and two of the reverse turns.