小说的原子水平结构细菌酯酶。
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伯恩PC, Isupov MN, Littlechild农协
小说的原子水平结构细菌酯酶。
结构。2000年2月15日,8 (2):143 - 51。
- PubMed ID
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10673440 (在PubMed]
- 文摘
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背景:一种新型细菌酯酶裂解酯对卤代环化合物分离出一个产碱杆菌属的物种。酯酶713由1062个碱基对编码基因。领导者的27个氨基酸序列的存在表明,这种酶细胞溶质的导出。酯酶713已经过度农杆菌属没有这个领袖序列。其氨基酸序列给出任何已知的蛋白质序列没有明显的同源性。结果:713年酯酶的晶体结构是由多个同形替换和精制为1。1一项决议。这个二聚的酶的亚基组成单个域α/β水解酶折叠。催化三已被确认为Ser206-His298-Glu230。催化三分子的酸性渣(Glu230)位于beta6链α/β水解酶的折叠,而其他大多数α/β水解酶酶有酸性渣位于beta7链。 The oxyanion hole is formed by the mainchain nitrogens of Cys71 and Gln207 as identified by the binding of a substrate analogue, (S)-7-iodo-2,3,4,5-tetrahydro-4-methyl-3-oxo-1H-1, 4-benzodiazepine-2-acetic acid. Cys71 forms a disulphide bond with the neighbouring Cys72. CONCLUSIONS: Despite negligible sequence homology, esterase 713 has structural similarities to a number of other esterases and lipases. Residues of the oxyanion hole were confirmed by structural comparison with Rhizomucor miehei lipase. It is proposed that completion of a functional active site requires the formation of the disulphide bond between adjacent residues Cys71 and Cys72 on export of the esterase into the oxidising environment of the periplasmic space.