View source for 8q7n


==cryo-EM structure of the human spliceosomal B complex protomer (tri-snRNP core region)==
<StructureSection load='8q7n' size='340' side='right'caption='[[8q7n]], [[Resolution|resolution]] 3.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8q7n]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8Q7N OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8Q7N FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.1&#8491;</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=8q7n FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8q7n OCA], [https://pdbe.org/8q7n PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8q7n RCSB], [https://www.ebi.ac.uk/pdbsum/8q7n PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8q7n ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SF3A1_HUMAN SF3A1_HUMAN] Subunit of the splicing factor SF3A 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.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The B complex is a key intermediate stage of spliceosome assembly. To improve the structural resolution of monomeric, human spliceosomal B (hB) complexes and thereby generate a more comprehensive hB molecular model, we determined the cryo-EM structure of B complex dimers formed in the presence of ATP gamma S. The enhanced resolution of these complexes allows a finer molecular dissection of how the 5' splice site (5'ss) is recognized in hB, and new insights into molecular interactions of FBP21, SNU23 and PRP38 with the U6/5'ss helix and with each other. It also reveals that SMU1 and RED are present as a heterotetrameric complex and are located at the interface of the B dimer protomers. We further show that MFAP1 and UBL5 form a 5' exon binding channel in hB, and elucidate the molecular contacts stabilizing the 5' exon at this stage. Our studies thus yield more accurate models of protein and RNA components of hB complexes. They further allow the localization of additional proteins and protein domains (such as SF3B6, BUD31 and TCERG1) whose position was not previously known, thereby uncovering new functions for B-specific and other hB proteins during pre-mRNA splicing.

Cryo-EM analyses of dimerized spliceosomes provide new insights into the functions of B complex proteins.,Zhang Z, Kumar V, Dybkov O, Will CL, Urlaub H, Stark H, Luhrmann R EMBO J. 2024 Mar;43(6):1065-1088. doi: 10.1038/s44318-024-00052-1. Epub 2024 Feb , 21. PMID:38383864<ref>PMID:38383864</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8q7n" style="background-color:#fffaf0;"></div>

==See Also==
*[[U5-15kD|U5-15kD]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Dybkov O]]
[[Category: Kumar V]]
[[Category: Luehrmann R]]
[[Category: Stark H]]
[[Category: Urlaub H]]
[[Category: Will CL]]
[[Category: Zhang Z]]