View source for 9oxe


==CRYO-EM STRUCTURE OF the human mPSF IN COMPLEX WITH THE AGUAAA poly(A) signal==
<StructureSection load='9oxe' size='340' side='right'caption='[[9oxe]], [[Resolution|resolution]] 2.53&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9oxe]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo Homo], [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Macaca_mulatta_polyomavirus_1 Macaca mulatta polyomavirus 1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9OXE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9OXE 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]] 2.53&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></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=9oxe FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9oxe OCA], [https://pdbe.org/9oxe PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9oxe RCSB], [https://www.ebi.ac.uk/pdbsum/9oxe PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9oxe ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CPSF1_HUMAN CPSF1_HUMAN] Component of the cleavage and polyadenylation specificity factor (CPSF) complex that plays a key role in pre-mRNA 3'-end formation, recognizing the AAUAAA signal sequence and interacting with poly(A) polymerase and other factors to bring about cleavage and poly(A) addition. This subunit is involved in the RNA recognition step of the polyadenylation reaction.<ref>PMID:14749727</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The 3'-end cleavage and polyadenylation of pre-mRNAs is dependent on a key hexanucleotide motif known as the polyadenylation signal (PAS). The PAS hexamer is recognized by the mammalian polyadenylation specificity factor (mPSF). AAUAAA is the most frequent PAS hexamer and together with AUUAAA, the second most frequent hexamer, account for approximately 75% of the poly(A) signals. The remaining hexamers are at low frequency (&lt;3%), and the molecular basis for their recognition is still not known. Here, we have determined the binding affinities for most of the PAS hexamers, showing that the Kd values are generally inversely correlated with their frequency. We also observed good cleavage activity for two low-frequency hexamers, AAGAAA and AACAAA. We have determined the cryo-electron microscopy structures of human mPSF in complex with AAUAAU and AGUAAA, at 3.1 and 2.5 A resolution, respectively. The overall binding modes of the two low-frequency hexamers are similar to that of AAUAAA, although the U3-A6 Hoogsteen base pair is disrupted in the AAUAAU hexamer. For AGUAAA, the G2 base undergoes a large conformational change, which allows it to maintain the hydrogen-bonding interaction with CPSF30 as observed with A2 and establish a new hydrogen bond to CPSF30.

Molecular basis for the recognition of low-frequency polyadenylation signals by mPSF.,Huang L, Chu HF, Tong L Nucleic Acids Res. 2025 Sep 5;53(17):gkaf890. doi: 10.1093/nar/gkaf890. PMID:40930529<ref>PMID:40930529</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9oxe" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo]]
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Macaca mulatta polyomavirus 1]]
[[Category: Chu H-F]]
[[Category: Huang L]]
[[Category: Tong L]]