REFINED CRYSTAL-STRUCTURE OF THE SERYL-TRANSFER RNA-SYNTHETASE FROM THERMUS-THERMOPHILUS AT 2-CENTER-DOT-5-ANGSTROM RESOLUTION
REFINED CRYSTAL-STRUCTURE OF THE SERYL-TRANSFER RNA-SYNTHETASE FROM THERMUS-THERMOPHILUS AT 2-CENTER-DOT-5-ANGSTROM RESOLUTION
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DOI：
10.1006/jmbi.1993.1576
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发表时间：
1993-11-05
影响因子：
5.6
通讯作者：
CUSACK, S
中科院分区：
文献类型：
--
作者：
FUJINAGA, M;BERTHETCOLOMINAS, C;CUSACK, S
测定了嗜热栖热菌丝氨酰-tRNA合成酶的三维结构，并在2.5 μ m分辨率下进行了精细化。最终的模型由每个421个残基和190个水分子的二聚体组成。在10 ~ 2.5 μ m分辨率范围内的所有数据的R因子为18.4%。其结构与大肠杆菌的同源酶非常相似，r.m.s.对于357个α-碳原子，相差1·5个碳原子被认为是等效的。这两种结构的比较表明增加的疏水性，降低构象熵和减少扭转应变作为可能的机制，通过该机制，在酶中获得的热稳定性从嗜热菌。
The three-dimensional structure of the seryl-tRNA synthetase fromThermus thermophilushas been determined and refined at 2·5 Å resolution. The final model consists of a dimer of 421 residues each and 190 water molecules. TheR-factor is 18·4% for all the data between 10 and 2·5 Å resolution. The structure is very similar to that of the homologous enzyme fromEscherichia coli, with an r.m.s. difference of 1·5 Å for the 357 α-carbon atoms considered equivalent. The comparison of the two structures indicates increased hydrophobicity, reduced conformational entropy and reduced torsional strain as possible mechanisms by which thermostability is obtained in the enzyme from the thermophile.