Spermidine-preferential Uptake System in Escherichia coli
Spermidine-preferential Uptake System in Escherichia coli
复制标题
大肠杆菌中的亚精胺优先摄取系统
DOI：
--
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发表时间：
1996
影响因子：
4.8
通讯作者：
K. Igarashi
中科院分区：
文献类型：
--
作者：
K. Kashiwagi;R. Pistocchi;Sanae Shibuya;S. Sugiyama;K. Morikawa;K. Igarashi
利用位点定向诱变制备的突变pod蛋白和突变pod蛋白的右外侧膜泡多胺转运活性，研究了大肠杆菌亚精胺优先摄取系统中外质底物结合蛋白pod蛋白上亚精胺的结合位点。突变的pod蛋白的多胺转运活性与其多胺结合活性相似。结果发现，pod蛋白的Trp-34、Thr-35、Glu-36、Tyr-37、Ser-83、Tyr-85、Asp-168、Glu-171、Trp-229、Trp-255、Asp-257、Tyr-293和Gln-327参与了与亚精胺的结合。当在表达突变的pod蛋白的完整细胞中测量亚精胺摄取活性时，发现与上述其他氨基酸相比，Glu-171、Trp-255和Asp-257更强烈地参与亚精胺与pod蛋白的结合。突变的pod蛋白在Glu-171、Trp-255和Asp-257位点的亚精胺解离常数与其他突变的pod蛋白相比显著增加。由于这三种氨基酸明显与亚精胺的二氨基丙烷部分相互作用，结果与pod蛋白对亚精胺的亲和力高于对腐胺的亲和力的发现相一致。发现腐胺在亚精胺的二氨基丁烷部分结合。
Spermidine-binding sites on PotD protein, a substrate-binding protein in periplasm, in the spermidine-preferential uptake system in Escherichia coli were studied by measuring polyamine transport activities of right-side-out membrane vesicles with mutated PotD proteins prepared by site-directed mutagenesis of the potD gene and by measuring polyamine binding activities of these mutated PotD proteins. Polyamine transport activities of the mutated PotD proteins paralleled their polyamine binding activities. It was found that Trp-34, Thr-35, Glu-36, Tyr-37, Ser-83, Tyr-85, Asp-168, Glu-171, Trp-229, Trp-255, Asp-257, Tyr-293, and Gln-327 of PotD protein were involved in the binding to spermidine. When spermidine uptake activities were measured in intact cells expressing the mutated PotD proteins, it was found that Glu-171, Trp-255, and Asp-257 were more strongly involved in the binding of spermidine to PotD protein than the other amino acids listed above. The dissociation constants of spermidine for the mutated PotD proteins at Glu-171, Trp-255, and Asp-257 increased greatly in comparison with those for the other mutated PotD proteins. Since these three amino acids clearly interact with the diaminopropane moiety of spermidine, the results are in accordance with the finding that PotD protein has a higher affinity for spermidine than for putrescine. Putrescine was found to bind at the position of the diaminobutane moiety of spermidine.
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DOI：
10.2210/pdb1laf/pdb
发表时间：
1995-07
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Byung-Ha Oh;G. Ames;Sung-HouK Kim
通讯作者：
Byung-Ha Oh;G. Ames;Sung-HouK Kim
影响因子：
11.2
作者：
Anthony E. Pegg
通讯作者：
Anthony E. Pegg
DOI：
10.2210/pdb1hpb/pdb
发表时间：
1995-01
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
B. Oh;C. Kang;H. D. Bondt;Sung-Hou Kim;K. Nikaido;A. Joshi;G. Ames
通讯作者：
B. Oh;C. Kang;H. D. Bondt;Sung-Hou Kim;K. Nikaido;A. Joshi;G. Ames
用构象特异性单克隆抗体分析，组氨酸结合蛋白在没有配体的情况下会发生构象变化。
DOI：
--
发表时间：
1994
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Wolf,A;Shaw,EW;Nikaido,K;Ames,GF
通讯作者：
Ames,GF