View source for 5wu5


==Crystal structure of apo human Tut1, form III==
<StructureSection load='5wu5' size='340' side='right'caption='[[5wu5]], [[Resolution|resolution]] 3.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5wu5]] is a 4 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=5WU5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5WU5 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 3.404&#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=5wu5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5wu5 OCA], [https://pdbe.org/5wu5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5wu5 RCSB], [https://www.ebi.ac.uk/pdbsum/5wu5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5wu5 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/STPAP_HUMAN STPAP_HUMAN] Poly(A) polymerase that creates the 3'-poly(A) tail of specific pre-mRNAs. Localizes to nuclear speckles together with PIP5K1A and mediates polyadenylation of a select set of mRNAs, such as HMOX1. In addition to polyadenylation, it is also required for the 3'-end cleavage of pre-mRNAs: binds to the 3'UTR of targeted pre-mRNAs and promotes the recruitment and assembly of the CPSF complex on the 3'UTR of pre-mRNAs. In addition to adenylyltransferase activity, also has uridylyltransferase activity. However, the ATP ratio is higher than UTP in cells, suggesting that it functions primarily as a poly(A) polymerase. Acts as a specific terminal uridylyltransferase for U6 snRNA in vitro: responsible for a controlled elongation reaction that results in the restoration of the four 3'-terminal UMP-residues found in newly transcribed U6 snRNA. Not involved in replication-dependent histone mRNA degradation.<ref>PMID:16790842</ref> <ref>PMID:18288197</ref> <ref>PMID:21102410</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The terminal uridylyltransferase, TUT1, builds or repairs the 3'-oligo-uridylylated tail of U6 snRNA. The 3'-oligo-uridylylated tail is the Lsm-binding site for U4/U6 di-snRNP formation and U6 snRNA recycling for pre-mRNA splicing. Here, we report crystallographic and biochemical analyses of human TUT1, which revealed the mechanisms for the specific uridylylation of the 3'-end of U6 snRNA by TUT1. The O2 and O4 atoms of the UTP base form hydrogen bonds with the conserved His and Asn in the catalytic pocket, respectively, and TUT1 preferentially incorporates UMP onto the 3'-end of RNAs. TUT1 recognizes the entire U6 snRNA molecule by its catalytic domains, N-terminal RNA-recognition motifs and a previously unidentified C-terminal RNA-binding domain. Each domain recognizes specific regions within U6 snRNA, and the recognition is coupled with the domain movements and U6 snRNA structural changes. Hence, TUT1 functions as the U6 snRNA-specific terminal uridylyltransferase required for pre-mRNA splicing.

Crystal structures of U6 snRNA-specific terminal uridylyltransferase.,Yamashita S, Takagi Y, Nagaike T, Tomita K Nat Commun. 2017 Jun 7;8:15788. doi: 10.1038/ncomms15788. PMID:28589955<ref>PMID:28589955</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 5wu5" style="background-color:#fffaf0;"></div>

==See Also==
*[[Poly(A) polymerase 3D structures|Poly(A) polymerase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Tomita K]]
[[Category: Yamashita S]]