8y7e
From Proteopedia
Cryo-EM Structure of the human minor pre-B complex (pre-precatalytic spliceosome) U12 snRNP part
Structural highlights
FunctionSF3B1_HUMAN Subunit of the splicing factor SF3B required for 'A' complex assembly formed by the stable binding of U2 snRNP to the branchpoint sequence (BPS) in pre-mRNA. Sequence independent binding of SF3A/SF3B complex upstream of the branch site is essential, it may anchor U2 snRNP to the pre-mRNA. May also be involved in the assembly of the 'E' complex. Belongs also to the minor U12-dependent spliceosome, which is involved in the splicing of rare class of nuclear pre-mRNA intron. Publication Abstract from PubMedThe 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. Structural basis of U12-type intron engagement by the fully assembled human minor spliceosome.,Bai R, Yuan M, Zhang P, Luo T, Shi Y, Wan R Science. 2024 Mar 15;383(6688):1245-1252. doi: 10.1126/science.adn7272. Epub 2024 , Mar 14. PMID:38484052[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Homo sapiens | Large Structures | Bai R | Luo T | Shi Y | Wan R | Yuan M | Zhang P
