ジャーナル: Cell Res / 年: 2018 タイトル: Structures of the human pre-catalytic spliceosome and its precursor spliceosome. 著者: Xiechao Zhan / Chuangye Yan / Xiaofeng Zhang / Jianlin Lei / Yigong Shi / 要旨: The pre-catalytic spliceosome (B complex) is preceded by its precursor spliceosome (pre-B complex) and followed by the activated spliceosome (B complex). The pre-B-to-B and B-to-B transitions are ...The pre-catalytic spliceosome (B complex) is preceded by its precursor spliceosome (pre-B complex) and followed by the activated spliceosome (B complex). The pre-B-to-B and B-to-B transitions are driven by the ATPase/helicases Prp28 and Brr2, respectively. In this study, we report the cryo-electron microscopy structures of the human pre-B complex and the human B complex at an average resolution of 5.7 and 3.8 Å, respectively. In the pre-B complex, U1 and U2 small nuclear ribonucleoproteins (snRNPs) associate with two edges of the tetrahedron-shaped U4/U6.U5 tri-snRNP. The pre-mRNA is yet to be recognized by U5 or U6 small nuclear RNA (snRNA), and loop I of U5 snRNA remains unengaged. In the B complex, U1 snRNP and Prp28 are dissociated, the 5'-exon is anchored to loop I of U5 snRNA, and the 5'-splice site is recognized by U6 snRNA through duplex formation. In sharp contrast to S. cerevisiae, most components of U2 snRNP and tri-snRNP, exemplified by Brr2, undergo pronounced rearrangements in the human pre-B-to-B transition. Structural analysis reveals mechanistic insights into the assembly and activation of the human spliceosome.
B: U5snRNA D: U5 small nuclear ribonucleoprotein 200 kDa helicase E: U5 small nuclear ribonucleoprotein 40 kDa protein a: Small nuclear ribonucleoprotein Sm D2 b: Small nuclear ribonucleoprotein F c: Small nuclear ribonucleoprotein E d: Small nuclear ribonucleoprotein G e: Small nuclear ribonucleoprotein Sm D3 f: Small nuclear ribonucleoprotein-associated proteins B and B' g: Small nuclear ribonucleoprotein Sm D1 F: U6snRNA q: U6 snRNA-associated Sm-like protein LSm2 r: U6 snRNA-associated Sm-like protein LSm3 s: U6 snRNA-associated Sm-like protein LSm4 t: U6 snRNA-associated Sm-like protein LSm5 x: U6 snRNA-associated Sm-like protein LSm6 y: U6 snRNA-associated Sm-like protein LSm7 z: U6 snRNA-associated Sm-like protein LSm8 G: pre-mRNA H: U2snRNA o: U2 small nuclear ribonucleoprotein A' p: U2 small nuclear ribonucleoprotein B'' h: Small nuclear ribonucleoprotein Sm D3 i: Small nuclear ribonucleoprotein-associated proteins B and B' j: Small nuclear ribonucleoprotein Sm D1 k: Small nuclear ribonucleoprotein Sm D2 m: Small nuclear ribonucleoprotein F l: Small nuclear ribonucleoprotein E n: Small nuclear ribonucleoprotein G u: Splicing factor 3A subunit 1 v: Splicing factor 3A subunit 2 w: Splicing factor 3A subunit 3 1: Splicing factor 3B subunit 1 2: Splicing factor 3B subunit 2 3: Splicing factor 3B subunit 3 4: Splicing factor 3B subunit 4 5: Splicing factor 3B subunit 6 6: PHD finger-like domain-containing protein 5A 7: Splicing factor 3B subunit 5 J: U4/U6 small nuclear ribonucleoprotein Prp3 K: U4/U6 small nuclear ribonucleoprotein Prp4 N: Pre-mRNA-processing factor 6 L: U4/U6 small nuclear ribonucleoprotein Prp31 M: NHP2-like protein 1 O: Thioredoxin-like protein 4A W: U4/U6.U5 tri-snRNP-associated protein 2 I: U4snRNA P: Small nuclear ribonucleoprotein Sm D2 Q: Small nuclear ribonucleoprotein F R: Small nuclear ribonucleoprotein E S: Small nuclear ribonucleoprotein G T: Small nuclear ribonucleoprotein Sm D3 U: Small nuclear ribonucleoprotein-associated proteins B and B' V: Small nuclear ribonucleoprotein Sm D1 X: Probable ATP-dependent RNA helicase DDX23 A: Pre-mRNA-processing-splicing factor 8 C: 116 kDa U5 small nuclear ribonucleoprotein component ヘテロ分子
分子量: 58536.105 Da / 分子数: 1 / 由来タイプ: 天然 / 由来: (天然) Homo sapiens (ヒト) / 参照: UniProt: O43172
#36: タンパク質
U4/U6smallnuclearribonucleoproteinPrp31 / Pre-mRNA-processing factor 31 / Serologically defined breast cancer antigen NY-BR-99 / U4/U6 snRNP ...Pre-mRNA-processing factor 31 / Serologically defined breast cancer antigen NY-BR-99 / U4/U6 snRNP 61 kDa protein / hPrp31
分子量: 55528.969 Da / 分子数: 1 / 由来タイプ: 天然 / 由来: (天然) Homo sapiens (ヒト) / 参照: UniProt: Q8WWY3