EIF1A

真核起始因子1A
	人類eIF1的溶液結構
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）是一種在真核翻譯起始進程中發揮重要作用的蛋白質，也是一種RNA結合蛋白。其主要的功能是穩定Met-tRNA_i與40S核糖體亞基間的結合，參與激活mRNA的結合，還可以通過結合到40S亞基上以阻止其與60S亞基結合形成無活性的核糖體。此外，43S前起始複合物在mRNA上尋找AUG起始密碼子的移動過程可能需要eIF1A的參與。^[1]在酵母中，eIF1A是維持其生存不可或缺的蛋白。^[2]

eIF1A被認為是最保守的起始因子：小麥和兔子的eIF1A在體外實驗中是可互換的；而且在體內實驗中，人eIF1A可以取代酵母eIF1A。^[3]^[4]^[2]eIF1A與原核生物中的IF1 同源。eIF1A與IF1結合核糖體相似的是，在沒有其他真核起始因子的協助下，eIF1A依然能夠結合到40S亞基上。^[5]

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

結構

eIF1A的結構採用了與大腸桿菌IF1相同的摺疊類型，即β桶的OB摺疊（β barrel oligomer-binding fold）。^[6]這種摺疊類型出現在很多參與翻譯的蛋白質中。eIF1A和IF1結構上的相似性提示兩者分別在真核和原核翻譯起始中有著相同的作用。

參考文獻

^ （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.

參見

真核起始因子
能夠與eIF1結合的真核起始因子：
- 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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