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-Structure paper
タイトル | Mechanism of 5' splice site transfer for human spliceosome activation. |
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ジャーナル・号・ページ | Science, Vol. 364, Issue 6438, Page 362-367, Year 2019 |
掲載日 | 2019年4月26日 |
![]() | Clément Charenton / Max E Wilkinson / Kiyoshi Nagai / ![]() |
PubMed 要旨 | The prespliceosome, comprising U1 and U2 small nuclear ribonucleoproteins (snRNPs) bound to the precursor messenger RNA 5' splice site (5'SS) and branch point sequence, associates with the U4/U6.U5 ...The prespliceosome, comprising U1 and U2 small nuclear ribonucleoproteins (snRNPs) bound to the precursor messenger RNA 5' splice site (5'SS) and branch point sequence, associates with the U4/U6.U5 tri-snRNP to form the fully assembled precatalytic pre-B spliceosome. Here, we report cryo-electron microscopy structures of the human pre-B complex captured before U1 snRNP dissociation at 3.3-angstrom core resolution and the human tri-snRNP at 2.9-angstrom resolution. U1 snRNP inserts the 5'SS-U1 snRNA helix between the two RecA domains of the Prp28 DEAD-box helicase. Adenosine 5'-triphosphate-dependent closure of the Prp28 RecA domains releases the 5'SS to pair with the nearby U6 ACAGAGA-box sequence presented as a mobile loop. The structures suggest that formation of the 5'SS-ACAGAGA helix triggers remodeling of an intricate protein-RNA network to induce Brr2 helicase relocation to its loading sequence in U4 snRNA, enabling Brr2 to unwind the U4/U6 snRNA duplex to allow U6 snRNA to form the catalytic center of the spliceosome. |
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手法 | EM (単粒子) |
解像度 | 2.9 - 28.0 Å |
構造データ | EMDB-4658, PDB-6qw6: EMDB-4665, PDB-6qx9: ![]() EMDB-4672: ![]() EMDB-4673: ![]() EMDB-4674: ![]() EMDB-4675: ![]() EMDB-4676: ![]() EMDB-4686: ![]() EMDB-4687: ![]() EMDB-4688: ![]() EMDB-4689: ![]() EMDB-4690: |
化合物 | ![]() ChemComp-IHP: ![]() ChemComp-MG: ![]() ChemComp-GTP: ![]() ChemComp-ZN: |
由来 |
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![]() | SPLICING / RNP complex / RNA / protein / spliceosome |