Plasmodium falciparum SSB tetramer wraps single-stranded DNA with similar topology but opposite polarity to E. coli SSB.
Plasmodium falciparum SSB tetramer wraps single-stranded DNA with similar topology but opposite polarity to E. coli SSB.
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DOI：
10.1016/j.jmb.2012.04.021
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发表时间：
2012-07-20
影响因子：
5.6
通讯作者：
Lohman, Timothy M.
中科院分区：
文献类型：
--
作者：
Antony, Edwin;Weiland, Elizabeth A.;Korolev, Sergey;Lohman, Timothy M.
单链DNA结合蛋白（SSB）在所有生物体的基因组维持中起着核心作用。恶性疟原虫是疟疾的病原体，它编码一种定位于顶质体的SSB蛋白，可能在顶质体基因组的复制和维持中起作用。f-SSB与细菌SSB蛋白具有高度的序列同源性，但其c端组成不同，在大肠杆菌SSB中，c端与十多种其他蛋白质相互作用。通过沉淀方法，我们发现Pf-SSB单独和与单链DNA结合时形成稳定的同型四聚体。我们还提出了一个2.1 Å分辨率的Pf-SSB四聚体结合两个（dT）35分子的晶体结构。Pf-SSB四聚体在结构上与大肠杆菌SSB四聚体相似，ssDNA以“棒球缝”拓扑结构完全包裹在四聚体周围，类似于大肠杆菌SSB的“65结合模式”。然而，包裹在Pf-SSB周围的ssDNA的极性与大肠杆菌SSB观察到的相反。DNA中碱基与氨基酸侧链之间的相互作用也与大肠杆菌SSB-DNA结构中观察到的不同，这表明这些结构相似的蛋白质的DNA结合特性可能存在其他差异。
Single stranded DNA binding (SSB) proteins play central roles in genome maintenance in all organisms. Plasmodium falciparum, the causative agent of malaria, encodes an SSB protein that localizes to the apicoplast and likely functions in the replication and maintenance of its genome. Pf-SSB shares a high degree of sequence homology with bacterial SSB proteins, but differs in the composition of its C-terminus, which in E. coli SSB interacts with more than a dozen other proteins. Using sedimentation methods we show that Pf-SSB forms a stable homo-tetramer alone and when bound to single stranded DNA. We also present a crystal structure at 2.1 Å resolution of the Pf-SSB tetramer bound to two (dT)35 molecules. The Pf-SSB tetramer is structurally similar to the E. coli SSB tetramer and ssDNA wraps completely around the tetramer with a “baseball seam” topology that is similar to E. coli SSB in its “65 binding mode”. However, the polarity of the ssDNA wrapping around Pf-SSB is opposite to that observed for E. coli SSB. The interactions between the bases in the DNA and the amino acids side chains also differ from those observed in the E. coli SSB-DNA structure suggesting that other differences may exist in the DNA binding properties of these structurally similar proteins.
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影响因子：
2.9
作者：
KRAUSS, G;SINDERMANN, H;MAASS, G
通讯作者：
MAASS, G
影响因子：
2.9
作者：
CURTH, U;GREIPEL, J;MAASS, G
通讯作者：
MAASS, G
影响因子：
2.9
作者：
LOHMAN, TM;BUJALOWSKI, W
通讯作者：
BUJALOWSKI, W
影响因子：
14.9
作者：
Fedorov, Roman;Witte, Gregor;Urbanke, Claus;Manstein, Dietmar J.;Curth, Ute
通讯作者：
Curth, Ute
DOI：
10.1111/j.1432-1033.1991.tb15789.x
发表时间：
1991-02-26
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
CURTH, U;BAYER, I;MAASS, G
通讯作者：
MAASS, G