40S核糖體次單元

真核小核糖體次單元（英文：Eukaryotic small ribosomal subunit）又稱40S核糖體次單元（40S ribosomal subunit），是80S核糖體的較小次單元，該核糖體的另一成分是60S核糖體次單元。「40S」和「60S」的名稱源於核糖體顆粒根據其沉降係數以Svedberg單位表示。它在結構和功能上與70S原核核糖體的30S核糖體次單元有關。^[1]^[2]^[3]^[4]^[5]但是，40S次單元比原核30S次單元大得多，並且包含許多其他蛋白質片段以及rRNA擴展片段。

功能

40S次單元包含一個解碼中心，該中心監控tRNA和mRNA在蛋白質轉譯中的互補性。它是包括43S和48S前起始複合體（PIC）的幾種轉譯起始複合體的最大組成部分，與多種真核起始因子如eIF1、eIF1A和eIF3結合。^[6]

參見

60S核糖體次單元

參考資料

^ 醫學主題詞表（MeSH）：40S+Ribosomal+Subunits
^ Rabl, J; Leibundgut, M; Ataide, SF; Haag, A; Ban, N. Crystal structure of the eukaryotic 40S ribosomal subunit in complex with initiation factor 1. Science. Feb 2011, 331 (6018): 730–736. PMID 21205638. doi:10.1126/science.1198308. hdl:20.500.11850/153130  .
^ Ben-Shem, A; Garreau; de Loubresse, N; Melnikov, S; Jenner, L; Yusupova, G; Yusupov, M. The structure of the eukaryotic ribosome at 3.0 Å resolution. Science. Dec 2011, 334 (6062): 1524–1529. PMID 22096102. doi:10.1126/science.1212642.
^ Wimberly, BT; Brodersen, DE; Clemons, WM Jr; Morgan-Warren, RJ; Carter, AP; Vonrhein, C; Hartsch, T; Ramakrishnan, V. Structure of the 30S ribosomal subunit. Nature. Sep 2000, 407 (6802): 327–339. PMID 11014182. doi:10.1038/35030006.
^ Schmeing, TM; Ramakrishnan, V. What recent ribosome structures have revealed about the mechanism of translation. Nature. Oct 2009, 461 (7268): 1234–1242. PMID 19838167. doi:10.1038/nature08403.
^ Aitken, Colin E.; Lorsch, Jon R. A mechanistic overview of translation initiation in eukaryotes. Nat. Struct. Mol. Biol. 2012, 19 (6): 568–576. PMID 22664984. doi:10.1038/nsmb.2303.

外部連結

Ribosomal Protein Gene Database (RPG) （頁面存檔備份，存於網際網路檔案館）

[1] 醫學主題詞表（MeSH）：40S+Ribosomal+Subunits

[Rabl-2] Rabl, J; Leibundgut, M; Ataide, SF; Haag, A; Ban, N. Crystal structure of the eukaryotic 40S ribosomal subunit in complex with initiation factor 1. Science. Feb 2011, 331 (6018): 730–736. PMID 21205638. doi:10.1126/science.1198308. hdl:20.500.11850/153130  .

[Ben-Shem-3] Ben-Shem, A; Garreau; de Loubresse, N; Melnikov, S; Jenner, L; Yusupova, G; Yusupov, M. The structure of the eukaryotic ribosome at 3.0 Å resolution. Science. Dec 2011, 334 (6062): 1524–1529. PMID 22096102. doi:10.1126/science.1212642.

[4] Wimberly, BT; Brodersen, DE; Clemons, WM Jr; Morgan-Warren, RJ; Carter, AP; Vonrhein, C; Hartsch, T; Ramakrishnan, V. Structure of the 30S ribosomal subunit. Nature. Sep 2000, 407 (6802): 327–339. PMID 11014182. doi:10.1038/35030006.

[Schmeing-5] Schmeing, TM; Ramakrishnan, V. What recent ribosome structures have revealed about the mechanism of translation. Nature. Oct 2009, 461 (7268): 1234–1242. PMID 19838167. doi:10.1038/nature08403.

[Aitken-6] Aitken, Colin E.; Lorsch, Jon R. A mechanistic overview of translation initiation in eukaryotes. Nat. Struct. Mol. Biol. 2012, 19 (6): 568–576. PMID 22664984. doi:10.1038/nsmb.2303.

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