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-Structure paper
タイトル | Structure of the mammalian ribosomal 43S preinitiation complex bound to the scanning factor DHX29. |
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ジャーナル・号・ページ | Cell, Vol. 153, Issue 5, Page 1108-1119, Year 2013 |
掲載日 | 2013年5月23日 |
著者 | Yaser Hashem / Amedee des Georges / Vidya Dhote / Robert Langlois / Hstau Y Liao / Robert A Grassucci / Christopher U T Hellen / Tatyana V Pestova / Joachim Frank / |
PubMed 要旨 | Eukaryotic translation initiation begins with assembly of a 43S preinitiation complex. First, methionylated initiator methionine transfer RNA (Met-tRNAi(Met)), eukaryotic initiation factor (eIF) 2, ...Eukaryotic translation initiation begins with assembly of a 43S preinitiation complex. First, methionylated initiator methionine transfer RNA (Met-tRNAi(Met)), eukaryotic initiation factor (eIF) 2, and guanosine triphosphate form a ternary complex (TC). The TC, eIF3, eIF1, and eIF1A cooperatively bind to the 40S subunit, yielding the 43S preinitiation complex, which is ready to attach to messenger RNA (mRNA) and start scanning to the initiation codon. Scanning on structured mRNAs additionally requires DHX29, a DExH-box protein that also binds directly to the 40S subunit. Here, we present a cryo-electron microscopy structure of the mammalian DHX29-bound 43S complex at 11.6 Å resolution. It reveals that eIF2 interacts with the 40S subunit via its α subunit and supports Met-tRNAi(Met) in an unexpected P/I orientation (eP/I). The structural core of eIF3 resides on the back of the 40S subunit, establishing two principal points of contact, whereas DHX29 binds around helix 16. The structure provides insights into eukaryote-specific aspects of translation, including the mechanism of action of DHX29. |
リンク | Cell / PubMed:23706745 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 11.6 Å |
構造データ | EMDB-5658: |
由来 |
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