PEPTIDE-CHAIN ELONGATION IN EUKARYOTES
PEPTIDE-CHAIN ELONGATION IN EUKARYOTES
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DOI：
10.1007/bf00986958
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发表时间：
1994-05-01
影响因子：
2.8
通讯作者：
PROUD, CG
中科院分区：
文献类型：
--
作者：
PROUD, CG
翻译的延伸阶段导致了信使核糖核酸的解码和相应多肽链的合成。在大多数真核生物中，两种不同的蛋白质延伸因子(EEF-1和EEF-2)是延伸所必需的。每一种都是与GTP形成的络合物。EEF-1是一种多聚体，介导同源氨基酰-tRNA与核糖体的结合，而EEF-2是一种单体，催化核糖体相对于mRNA的运动。最近的工作表明，细菌核糖体具有三个tRNA结合位点，并且在伸长过程中tRNAs可能占据‘杂交’位点，被纳入真核伸长模型。在真菌中，伸长还需要第三个因素，EEF-3。有许多机制可以提高延伸率的准确性或“保真度”：EEF-3可能在这方面发挥了作用。该延伸因子和其他延伸因子的cDNA已被克隆和测序，并讨论了延伸因子的结构和功能特性，EEF-1和EEF-2可以通过磷酸化来调节，这可能有助于控制体内的延伸速度。
The elongation phase of translation leads to the decoding of the mRNA and the synthesis of the corresponding polypeptide chain. In most eukaryotes, two distinct protein elongation factors (eEF-1 and eEF-2) are required for elongation. Each is active as a complex with GTP. eEF-1 is a multimer and mediates the binding of the cognate aminoacyl-tRNA to the ribosome, while eEF-2, a monomer, catalyses the movement of the ribosome relative to the mRNA. Recent work showing that bacterial ribosomes possess three sites for tRNA binding and that during elongation tRNAs may occupy 'hybrid' sites is incorporated into a model of eukaryotic elongation. In fungi, elongation also requires a third factor, eEF-3. A number of mechanisms exist to promote the accuracy or 'fidelity' of elongation: eEF-3 may play a role here. cDNAs for this and the other elongation factors have been cloned and sequenced, and the structural and functional properties of the elongation factors are discussed, eEF-1 and eEF-2 can be regulated by phosphorylation, and this may serve to control rates of elongation in vivo.