A protein constructed de novo enables cell growth by altering gene regulation
A protein constructed de novo enables cell growth by altering gene regulation
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DOI：
10.1073/pnas.1600566113
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发表时间：
2016-03-01
影响因子：
11.1
通讯作者：
Hecht, Michael H.
中科院分区：
文献类型：
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作者：
Digianantonio, Katherine M.;Hecht, Michael H.
蛋白质设计的最新进展依赖于理性和计算方法来创建折叠和功能的新序列。相比之下，自然系统在没有任何先验设计的情况下选择功能蛋白质。为了模仿自然，我们使用了大量的新序列文库，并选择了一些功能蛋白来拯救条件必需基因缺失的大肠杆菌细胞。通过这种方式，新蛋白SynSerB3被选为细胞的救助者，其中编码丝氨酸生物合成所必需的磷酸丝氨酸磷酸酶的Serb基因被缺失。然而，SynSerB3不能通过催化磷酸丝氨酸的水解来挽救缺失的活性。相反，SynSerB3上调了hisb，这是一种编码组氨醇磷酸酶的基因。这种内源性的大肠杆菌磷酸酶具有杂乱的活性，当过度表达时，可以补偿磷酸丝氨酸磷酸酶的缺失。因此，从头蛋白SynSerB3通过改变His操纵子的自然调节来挽救Serb的缺失。
Recent advances in protein design rely on rational and computational approaches to create novel sequences that fold and function. In contrast, natural systems selected functional proteins without any design a priori. In an attempt to mimic nature, we used large libraries of novel sequences and selected for functional proteins that rescue Escherichia coli cells in which a conditionally essential gene has been deleted. In this way, the de novo protein SynSerB3 was selected as a rescuer of cells in which serB, which encodes phosphoserine phosphatase, an enzyme essential for serine biosynthesis, was deleted. However, SynSerB3 does not rescue the deleted activity by catalyzing hydrolysis of phosphoserine. Instead, SynSerB3 upregulates hisB, a gene encoding histidinol phosphate phosphatase. This endogenous E. coli phosphatase has promiscuous activity that, when overexpressed, compensates for the deletion of phosphoserine phosphatase. Thus, the de novo protein SynSerB3 rescues the deletion of serB by altering the natural regulation of the His operon.