EIF1A

真核起始因子1A
	人类eIF1的溶液结构
識別
符號	eIF1A
Entrez	9086
OMIM	400014
PDB	2d7q
RefSeq	NP_004672
UniProt	O14602
其他資料
基因座	21 [1]

eIF1A（eukaryotic translation initiation factor 1A，真核起始因子1A）是一种在真核翻译起始进程中发挥重要作用的蛋白质，也是一种RNA结合蛋白。其主要的功能是稳定Met-tRNA_i与40S核糖体亚基间的结合，参与激活mRNA的结合，还可以通过结合到40S亚基上以阻止其与60S亚基结合形成无活性的核糖体。此外，43S前起始复合物在mRNA上寻找AUG起始密码子的移动过程可能需要eIF1A的参与。^[1]在酵母中，eIF1A是维持其生存不可或缺的蛋白。^[2]

eIF1A被认为是最保守的起始因子：小麦和兔子的eIF1A在体外实验中是可互换的；而且在体内实验中，人eIF1A可以取代酵母eIF1A。^[3]^[4]^[2]eIF1A与原核生物中的IF1 同源。eIF1A与IF1结合核糖体相似的是，在没有其他真核起始因子的协助下，eIF1A依然能够结合到40S亚基上。^[5]

eIF1A的基因存在于X染色体（基因名：EIF1AX）和Y染色体（基因名：EIF1AY）中。

结构

eIF1A的结构采用了与大肠杆菌IF1相同的折叠类型，即β桶的OB折叠（β barrel oligomer-binding fold）。^[6]这种折叠类型出现在很多参与翻译的蛋白质中。eIF1A和IF1结构上的相似性提示两者分别在真核和原核翻译起始中有着相同的作用。

参考文献

^ （英文）Pestova TV, Borukhov SI, Hellen CU. Eukaryotic ribosomes require initiation factors 1 and 1A to locate initiation codons. Nature. 1998, 394: 854–9. PMID 9732867.
^ ^2.0 ^2.1 （英文）Wei CL, Kainuma M, Hershey JW. Characterization of yeast translation initiation factor 1A and cloning of its essential gene. J Biol Chem. 1995, 270: 22788–94. PMID 7559407.
^ （英文）Timmer RT, Lax SR, Hughes DL, Merrick WC, Ravel JM, Browning KS. Characterization of wheat germ protein synthesis initiation factor eIF-4C and comparison of eIF-4C from wheat germ and rabbit reticulocytes. J Biol Chem. 1993, 268 (33): 24863–7. PMID 8227048.
^ （英文）Dever TE, Wei CL, Benkowski LA, Browning K, Merrick WC, Hershey JW. Determination of the amino acid sequence of rabbit, human, and wheat germ protein synthesis factor eIF-4C by cloning and chemical sequencing. J Biol Chem. 1994, 269: 3212–8. PMID 8106356.
^ （英文）Majumdar R, Bandyopadhyay A, Maitra U. Mammalian translation initiation factor eIF1 functions with eIF1A and eIF3 in the formation of a stable 40 S preinitiation complex. J Biol Chem. 2003, 278: 6580–7. PMID 12493757.
^ （英文）Battiste JL, Pestova TV, Hellen CU, Wagner G. The eIF1A solution structure reveals a large RNA-binding surface important for scanning function. Mol Cell. 2000, 5: 109–19. PMID 10678173.

参见

真核起始因子
能够与eIF1结合的真核起始因子：
- eIF2
- eIF3
- eIF5B

[1] （英文）Pestova TV, Borukhov SI, Hellen CU. Eukaryotic ribosomes require initiation factors 1 and 1A to locate initiation codons. Nature. 1998, 394: 854–9. PMID 9732867.

[wei-2] 2.0 ^2.1 （英文）Wei CL, Kainuma M, Hershey JW. Characterization of yeast translation initiation factor 1A and cloning of its essential gene. J Biol Chem. 1995, 270: 22788–94. PMID 7559407.

[3] （英文）Timmer RT, Lax SR, Hughes DL, Merrick WC, Ravel JM, Browning KS. Characterization of wheat germ protein synthesis initiation factor eIF-4C and comparison of eIF-4C from wheat germ and rabbit reticulocytes. J Biol Chem. 1993, 268 (33): 24863–7. PMID 8227048.

[4] （英文）Dever TE, Wei CL, Benkowski LA, Browning K, Merrick WC, Hershey JW. Determination of the amino acid sequence of rabbit, human, and wheat germ protein synthesis factor eIF-4C by cloning and chemical sequencing. J Biol Chem. 1994, 269: 3212–8. PMID 8106356.

[5] （英文）Majumdar R, Bandyopadhyay A, Maitra U. Mammalian translation initiation factor eIF1 functions with eIF1A and eIF3 in the formation of a stable 40 S preinitiation complex. J Biol Chem. 2003, 278: 6580–7. PMID 12493757.

[6] （英文）Battiste JL, Pestova TV, Hellen CU, Wagner G. The eIF1A solution structure reveals a large RNA-binding surface important for scanning function. Mol Cell. 2000, 5: 109–19. PMID 10678173.

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