Crystal structure of elongation factor P from Pseudomonas aeruginosa at 1.75 Å resolution
Crystal structure of elongation factor P from Pseudomonas aeruginosa at 1.75 Å resolution
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DOI：
10.1002/prot.22992
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发表时间：
2011-05-01
影响因子：
2.9
通讯作者：
Choe, Jungwoo
中科院分区：
文献类型：
--
作者：
Choi, Sarah;Choe, Jungwoo
信使RNA翻译成蛋白质需要核糖体和各种翻译因子之间的相互作用。1其中，延伸因子P（EF-P）通过促进第一个肽键的合成，刺激70 S核糖体的肽基转移酶活性。2，3 EF-P在细菌中普遍保守，并且对于大肠杆菌的生存力是必需的。4. EF-P功能的中断已被证明会导致细胞死亡，因为蛋白质合成的缺陷。在细胞中，每个核糖体大约有0.1-0.2个EF-P拷贝，这个比例与其他起始因子相似。7-10 eIF-5A通过脱氧羟腐胺赖氨酸合成酶和脱氧羟腐胺赖氨酸羟化酶进行非常保守的赖氨酸残基至羟腐胺赖氨酸的翻译后修饰;这种修饰对于酵母的生存力是必需的。11，12相应的残基（赖氨酸或精氨酸）在细菌EF-P中是高度保守的。GenX是赖氨酰-tRNA合成酶的一个副产物，它将赖氨酰部分转移到E.杆菌13先前确定的EF-P的晶体结构表明，它有三个b-桶结构域，其整体形状和尺寸与tRNA惊人地相似。7 EF-P与70 S核糖体、起始tRNA和mRNA复合物的结构表明，EF-P与核糖体的P-和E-位点之间的结合不同于经典的tRNA结合位点，并且与起始tRNA和其他核糖体组分如核糖体L1蛋白相互作用。图14当E-位点为空时，起始tRNA占据初始P/I位点。15 EF-P的作用是将起始物tRNA置于P位点，使得起始物tRNA的N-甲酰甲硫氨酸可以正确地定位在肽基转移中心（PTC）中，用于第一个肽键的形成。14，16在这项研究中，我们报告了铜绿假单胞菌EF-P在1.75 A的晶体结构。我们分析了铜绿假单胞菌EF-P的构象变化，并与先前确定的EF-P结构进行了比较，提出了保守的表面残基的功能作用，包括C-末端环，这在以前的结构中往往是无序的。
The translation of messenger RNA to protein requires an interplay between the ribosome and various translation factors. 1 Among them, elongation factor P (EF-P) stimulates the peptidyltransferase activity of 70S ribosome, by promoting the synthesis of the first peptide bond. 2, 3 EF-P is universally conserved in bacteria and is essential for the viability of Escherichia coli. 4 The interruption of EF-P function has been shown to result in cell death, because of a defect in protein synthesis. 5 There are about 0.1–0.2 copies of EF-P’s per ribosome in the cell, a ratio that is similar to other initiation factors. 6 Archaea and eukarya have translation initiation factor 5A (eIF-5A), which shares sequence and structural similarities to the first two domains of bacterial EF-P. 7–10 eIF-5A undergoes a posttranslational modification of a very well-conserved lysine residue to hypusine, by deoxyhypusine synthase and deoxyhypusine hydroxylase; this modification is essential for the viability of yeast. 11, 12 The corresponding residue (either lysine or arginine) is strongly conserved in bacterial EF-P. GenX, a paralog of lysyl-tRNA synthetase, transfers a lysyl moiety to this conserved residue in E. coli. 13 Previously determined crystal structures of EF-P showed that it has three b-barrel domains and its overall shape and dimension is strikingly similar to those of tRNA. 7 The structure of EF-P in complex with 70S ribosome, initiator tRNA, and mRNA showed that it binds to the ribosome between the P-and E-site differently from the classical tRNA binding sites, and interacts with initiator tRNA and other ribosomal components, such as ribosomal L1 protein. 14 The initiator tRNA occupies the preliminary P/I site when the E-site is empty. 15 The role of EF-P is to place the initiator tRNA into the P site so that the N-formylmethionine of initiator tRNA can be correctly positioned in the peptidyl transfer center (PTC) for the first peptide bond formation. 14, 16 In this study, we report the crystal structure of Pseudomonas aeruginosa EF-P at 1.75 A. We analyzed the conformational changes of P. aeruginosa EF-P in comparison with the previously determined EF-P structures, and proposed the functional roles of conserved surface residues including the C-terminal loop, which was often disordered in the previous structures.