ORIENTATIONS OF TRANSFER-RNA IN THE RIBOSOMAL A-SITE AND P-SITE
ORIENTATIONS OF TRANSFER-RNA IN THE RIBOSOMAL A-SITE AND P-SITE
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DOI：
10.1093/nar/22.18.3779
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发表时间：
1994-09-11
影响因子：
14.9
通讯作者：
HARVEY, SC
中科院分区：
文献类型：
--
作者：
EASTERWOOD, TR;MAJOR, F;HARVEY, SC
在蛋白质合成中，肽键的形成需要携带氨基酸的tRNA （A位点tRNA）与携带生长肽链的tRNA （P位点tRNA）在它们的3'端接触。对于两种trna在核糖体中与mRNA结合时的取向，提出了两种模型。将tRNA视为一个倒置的L，反密码子环朝下，受体干朝右，并称之为正面视图，R （Rich）模型将使P位点tRNA的背面面向A位点tRNA的正面。在S （Sundaralingam）模型中，P位点tRNA的前部与A位点tRNA的后部相对。使用MC-SYM创建了两个trna与mRNA结合的模型，因为它们将定位在核糖体A和P位点，MC-SYM是一种用于构建核酸结构的约束满足搜索程序。该模型结合了荧光能量转移实验和化学交联的信息。最好回答约束的模型是S型的，没有产生与约束一致的R构象。
In protein synthesis, peptide bond formation requires that the tRNA carrying the amino acid (A site tRNA) contact the tRNA carrying the growing peptide chain (P site tRNA) at their 3' termini. Two models have been proposed for the orientations of two tRNAs as they would be bound to the mRNA in the ribosome. Viewing the tRNA as an upside down L, anticodon loop pointing down, acceptor stem pointing right, and calling this the front view, the R (Rich) model would have the back of the P site tRNA facing the front of the A site tRNA. In the S (Sundaralingam) model the front of the P site tRNA faces the back of the A site tRNA. Models of two tRNAs bound to mRNA as they would be positioned in the ribosomal A and P sites have been created using MC-SYM, a constraint satisfaction search program designed to build nucleic acid structures. The models incorporate information from fluorescence energy transfer experiments and chemical crosslinks. The models that best answer the constraints are of the S variety, with no R conformations produced consistent with the constraints.