National Natural Science Foundation of China (NSFC)
32171214
中国
National Natural Science Foundation of China (NSFC)
31930059
中国
National Natural Science Foundation of China (NSFC)
32100987
中国
引用
ジャーナル: Science / 年: 2024 タイトル: Structural basis of U12-type intron engagement by the fully assembled human minor spliceosome. 著者: Rui Bai / Meng Yuan / Pu Zhang / Ting Luo / Yigong Shi / Ruixue Wan / 要旨: The minor spliceosome, which is responsible for the splicing of U12-type introns, comprises five small nuclear RNAs (snRNAs), of which only one is shared with the major spliceosome. In this work, we ...The minor spliceosome, which is responsible for the splicing of U12-type introns, comprises five small nuclear RNAs (snRNAs), of which only one is shared with the major spliceosome. In this work, we report the 3.3-angstrom cryo-electron microscopy structure of the fully assembled human minor spliceosome pre-B complex. The atomic model includes U11 small nuclear ribonucleoprotein (snRNP), U12 snRNP, and U4atac/U6atac.U5 tri-snRNP. U11 snRNA is recognized by five U11-specific proteins (20K, 25K, 35K, 48K, and 59K) and the heptameric Sm ring. The 3' half of the 5'-splice site forms a duplex with U11 snRNA; the 5' half is recognized by U11-35K, U11-48K, and U11 snRNA. Two proteins, CENATAC and DIM2/TXNL4B, specifically associate with the minor tri-snRNP. A structural analysis uncovered how two conformationally similar tri-snRNPs are differentiated by the minor and major prespliceosomes for assembly.