Signal peptide-chaperone interactions on the twin-arginine protein transport pathway
Signal peptide-chaperone interactions on the twin-arginine protein transport pathway
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DOI：
10.1073/pnas.0500737102
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发表时间：
2005-06-14
影响因子：
11.1
通讯作者：
Sargent, F
中科院分区：
文献类型：
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作者：
Hatzixanthis, K;Clarke, TA;Sargent, F
双精氨酸转运（Tat）系统是原核生物和叶绿体的蛋白质靶向途径。大多数大肠杆菌Tat底物是复杂的金属酶，在运输前必须正确折叠和组装，因此出口前的伴侣介导的“校对”过程正在进行中。范式校对伴侣是TorD，它协调关键呼吸酶三甲胺n -氧化物还原酶（TorA）的成熟和输出。研究表明，纯化的TorD在体外与TorA双精氨酸信号肽紧密结合，并具有良好的特异性。据报道，TorD家族构成了迄今为止意想不到的一类核苷酸结合蛋白。TorD对GTP的亲和力通过初始信号肽结合而增强，并提出GTP控制着Tat校对过程中信号肽的结合和释放周期。
The twin-arginine transport (Tat) system is a protein-targeting pathway of prokaryotes and chloroplasts. Most Escherichia coli Tat substrates are complex metalloenzymes that must be correctly folded and assembled before transport, and a preexport chaperone-mediated "proofreading" process is therefore in operation. The paradigm proofreading chaperone is TorD, which coordinates maturation and export of the key respiratory enzyme trimethylamine N-oxide reductase (TorA). It is demonstrated here that purified TorD binds tightly and with exquisite specificity to the TorA twin-arginine signal peptide in vitro. It is also reported that the TorD family constitutes a hitherto unexpected class of nucleotide-binding proteins. The affinity of TorD for GTP is enhanced by initial signal peptide binding, and it is proposed that GTP governs signal peptide binding-and-release cycles during Tat proofreading.