Identification of the prolyl isomerase domain of Escherichia coli trigger factor
Identification of the prolyl isomerase domain of Escherichia coli trigger factor
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DOI：
10.1016/0014-5793(96)00351-1
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发表时间：
1996-04-29
期刊：
影响因子：
3.5
通讯作者：
Bukau, B
中科院分区：
文献类型：
--
作者：
Hesterkamp, T;Bukau, B
大肠杆菌触发因子是一种48kda的蛋白质，最近被鉴定为一种核糖体结合的肽酰脯氨酸顺式反异构酶（PPIase），能够在体外催化蛋白质折叠。我们发现触发因子与新生多肽链相关，提示在蛋白质的共翻译折叠中起作用。序列比较显示触发因子片段与FK506结合蛋白（FKBP）家族的PPIases具有同源性。在这里，我们报道了通过蛋白水解片段的微测序和质谱分析纯化触发因子及其多肽链的结构域分配。在体外实验中，两种蛋白酶产生的分子量为12-13 kDa的片段包含了预测的FKBP结构域，并具有PPIase活性。已知触发因子蛋白的序列比对表明，在该蛋白的中心功能域内具有高度的保守性。
E. coli trigger factor is a protein of 48 kDa which was recently identified as a ribosome-bound peptidyl-prolyl-cisltransisomerase (PPIase) capable of catalysing protein folding in vitro. We found trigger factor in association with nascent polypeptide chains, suggesting a function in the co-translational folding of proteins. Sequence comparisons revealed a homology of a segment of trigger factor with PPIases of the FK506 binding protein (FKBP) family. Here, we report on the purification of trigger factor and a domain assignment of its polypeptide chain by microsequencing and mass spectroscopy of proteolytic fragments. Two proteases generated fragments of 12-13 kDa molecular weight that encompass the predicted FKBP domain and possess PPIase activity in vitro. Sequence alignment of the known trigger factor proteins demonstrates a high degree of conservation within this central functional domain of the protein.