(二)真核生物翻译起始复合 物形成 生物化学与分子生物学教研室
eIF3eIF2BeIF6 60S Ribosome 80S 40S eIF5 GTP GT eIF3eIF2BeIF6 GDP Pi 40S eIF4E eIF3eIF2BeIF6 eIF4G eIF2111 PAB GTP 40S eIF4A eIF3eIF2BeIF6 eIF4E GTP eIF4G ATPADP PAB eIF4A Pi 生物化学与分子生物学教研室
Ribosome + ATP Pi ADP + eIF4A PAB eIF4G eIF4E GTP eIF2 eIF3eIF2B eIF6 60S 80S GDP + Pi eIF5 GTP GTP 40S eIF4A PAB eIF4G eIF4E eIF3eIF2B eIF6 40S eIF3eIF2B eIF6 40S GTP eIF2 eIF3eIF2B eIF6
ribosome 40 s small subunit 5'cap elF-3 eIF-4E 3'polyA tail eIF-4G polyA binding protein mRNA AUG UAA■ coding sequence The interaction among the several initiated factors and 5'cap and 3'polyA tail on mRNA and ribosome small subunit in eukaryotic translational initiation stage 生物化学与分子生物学教研室
coding sequence ribosome 40 s small subunit 5’ cap 3’ polyA tail eIF-3 eIF-4E eIF-4G polyA binding protein mRNA The interaction among the several initiated factors and 5’ cap and 3’ polyA tail on mRNA and ribosome small subunit in eukaryotic translational initiation stage
二、肽链的延长 根据mRNA密码序列的指导，依次添加氨基酸从N端向 C端延长肽链，直到合成终止的过程，又称为核蛋白体循环。 (ribosomal cycle)。每次循环增加一个氨基酸，分为三步： ●进位(entrance） ●成肽 (peptide bond formation) 转位(translocation) 延长过程所需要的蛋白质因子称为 延长因子(elongation factor) 生物化学与分子生物学教研室
The elongation of translation AUG The complex of translated initiation ■ The aminoacyl-tRNA GTP A guanosine triphosphate EF-Tu EF-Ts The elongation factors EF-G 生物化学与分子生物学教研室
The elongation of translation The complex of translated initiation 2 3 n The aminoacyl-tRNA GTP A guanosine triphosphate EF-Tu EF-Ts EF-G The elongation factors 1 AUG