3hl4

<StructureSection load='3hl4' size='340' side='right' caption='[[3hl4]], [[Resolution|resolution]] 2.20&Aring;' scene=''>

<table><tr><td colspan='2'>[[3hl4]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Buffalo_rat Buffalo rat]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3HL4 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3HL4 FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CDC:[2-CYTIDYLATE-O-PHOSPHONYLOXYL]-ETHYL-TRIMETHYL-AMMONIUM'>CDC</scene>, <scene name='pdbligand=FMT:FORMIC+ACID'>FMT</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene></td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">Ctpct, Pcyt1, Pcyt1a ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=10116 Buffalo rat])</td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Choline-phosphate_cytidylyltransferase Choline-phosphate cytidylyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.15 2.7.7.15] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3hl4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3hl4 OCA], [http://pdbe.org/3hl4 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3hl4 RCSB], [http://www.ebi.ac.uk/pdbsum/3hl4 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3hl4 ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/PCY1A_RAT PCY1A_RAT]] Controls phosphatidylcholine synthesis.

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== Publication Abstract from PubMed ==

CTP:phosphocholine cytidylyltransferase (CCT) is the key regulatory enzyme in the synthesis of phosphatidylcholine, the most abundant phospholipid in eukaryotic cell membranes. The CCT-catalyzed transfer of a cytidylyl group from CTP to phosphocholine to form CDP-choline is regulated by a membrane lipid-dependent mechanism imparted by its C-terminal membrane binding domain. We present the first analysis of a crystal structure of a eukaryotic CCT. A deletion construct of rat CCTalpha spanning residues 1-236 (CCT236) lacks the regulatory domain and as a result displays constitutive activity. The 2.2-A structure reveals a CCT236 homodimer in complex with the reaction product, CDP-choline. Each chain is composed of a complete catalytic domain with an intimately associated N-terminal extension, which together with the catalytic domain contributes to the dimer interface. Although the CCT236 structure reveals elements involved in binding cytidine that are conserved with other members of the cytidylyltransferase superfamily, it also features nonconserved active site residues, His-168 and Tyr-173, that make key interactions with the beta-phosphate of CDP-choline. Mutagenesis and kinetic analyses confirmed their role in phosphocholine binding and catalysis. These results demonstrate structural and mechanistic differences in a broadly conserved protein fold across the cytidylyltransferase family. Comparison of the CCT236 structure with those of other nucleotidyltransferases provides evidence for substrate-induced active site loop movements and a disorder-to-order transition of a loop element in the catalytic mechanism.

Crystal structure of a mammalian CTP: phosphocholine cytidylyltransferase catalytic domain reveals novel active site residues within a highly conserved nucleotidyltransferase fold.,Lee J, Johnson J, Ding Z, Paetzel M, Cornell RB J Biol Chem. 2009 Nov 27;284(48):33535-48. Epub 2009 Sep 25. PMID:19783652<ref>PMID:19783652</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 3hl4" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Buffalo rat]]

[[Category: Choline-phosphate cytidylyltransferase]]

[[Category: Cornell, R B]]

[[Category: Lee, J]]

[[Category: Paetzel, M]]

[[Category: Transferase]]