View source for 4fh3


==Crystal structures of the Cid1 poly (U) polymerase reveal the mechanism for UTP selectivity==
<StructureSection load='4fh3' size='340' side='right'caption='[[4fh3]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4fh3]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Schizosaccharomyces_pombe_972h- Schizosaccharomyces pombe 972h-]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4FH3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4FH3 FirstGlance]. <br>
</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=4fh3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4fh3 OCA], [https://pdbe.org/4fh3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4fh3 RCSB], [https://www.ebi.ac.uk/pdbsum/4fh3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4fh3 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CID1_SCHPO CID1_SCHPO] Involved in cell cycle arrest where in association with crb2/rhp9 and chk1 it inhibits unscheduled mitosis.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Polyuridylation is emerging as a ubiquitous post-translational modification with important roles in multiple aspects of RNA metabolism. These poly (U) tails are added by poly (U) polymerases with homology to poly (A) polymerases; nevertheless, the selection for UTP over ATP remains enigmatic. We report the structures of poly (U) polymerase Cid1 from Schizoscaccharomyces pombe alone and in complex with UTP, CTP, GTP and 3'-dATP. These structures reveal that each of the 4 nt can be accommodated at the active site; however, differences exist that suggest how the polymerase selects UTP over the other nucleotides. Furthermore, we find that Cid1 shares a number of common UTP recognition features with the kinetoplastid terminal uridyltransferases. Kinetic analysis of Cid1's activity for its preferred substrates, UTP and ATP, reveal a clear preference for UTP over ATP. Ultimately, we show that a single histidine in the active site plays a pivotal role for poly (U) activity. Notably, this residue is typically replaced by an asparagine residue in Cid1-family poly (A) polymerases. By mutating this histidine to an asparagine residue in Cid1, we diminished Cid1's activity for UTP addition and improved ATP incorporation, supporting that this residue is important for UTP selectivity.

Crystal structures of the Cid1 poly (U) polymerase reveal the mechanism for UTP selectivity.,Lunde BM, Magler I, Meinhart A Nucleic Acids Res. 2012 Aug 9. PMID:22885303<ref>PMID:22885303</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4fh3" style="background-color:#fffaf0;"></div>

==See Also==
*[[Poly(A) RNA polymerase|Poly(A) RNA polymerase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Schizosaccharomyces pombe 972h-]]
[[Category: Lunde BM]]
[[Category: Magler I]]
[[Category: Meinhart A]]