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| | ==Crystal Structure of a Mammalian Cytidylyltransferase== | | ==Crystal Structure of a Mammalian Cytidylyltransferase== |
| - | <StructureSection load='4mvd' size='340' side='right' caption='[[4mvd]], [[Resolution|resolution]] 8.00Å' scene=''> | + | <StructureSection load='4mvd' size='340' side='right'caption='[[4mvd]], [[Resolution|resolution]] 8.00Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4mvd]] is a 8 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=4MVD OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4MVD FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4mvd]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4MVD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4MVD 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></td></tr> | + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CDC:[2-CYTIDYLATE-O-PHOSPHONYLOXYL]-ETHYL-TRIMETHYL-AMMONIUM'>CDC</scene></td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3hl4|3hl4]], [[4mvc|4mvc]]</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=4mvd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4mvd OCA], [https://pdbe.org/4mvd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4mvd RCSB], [https://www.ebi.ac.uk/pdbsum/4mvd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4mvd ProSAT]</span></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>
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| - | <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=4mvd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4mvd OCA], [http://pdbe.org/4mvd PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4mvd RCSB], [http://www.ebi.ac.uk/pdbsum/4mvd PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4mvd ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/PCY1A_RAT PCY1A_RAT]] Controls phosphatidylcholine synthesis. | + | [https://www.uniprot.org/uniprot/PCY1A_RAT PCY1A_RAT] Controls phosphatidylcholine synthesis. |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Buffalo rat]] | + | [[Category: Large Structures]] |
| - | [[Category: Choline-phosphate cytidylyltransferase]] | + | [[Category: Rattus norvegicus]] |
| - | [[Category: Cornell, R B]] | + | [[Category: Cornell RB]] |
| - | [[Category: Lee, J]] | + | [[Category: Lee J]] |
| - | [[Category: Amphipathic helix]]
| + | |
| - | [[Category: Cytidine 5'-diphosphocholine synthesis]]
| + | |
| - | [[Category: Endoplasmic reticulum]]
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| - | [[Category: Four-helix bundle]]
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| - | [[Category: Lipid membrane binding]]
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| - | [[Category: Lipid membrane surface]]
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| - | [[Category: Nucleus]]
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| - | [[Category: Phosphatidylcholine homeostasis]]
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| - | [[Category: Rossmann fold]]
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| - | [[Category: Transferase]]
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| Structural highlights
Function
PCY1A_RAT Controls phosphatidylcholine synthesis.
Publication Abstract from PubMed
CTP:phosphocholine cytidylyltransferase (CCT) interconverts between an inactive soluble and active membrane-bound form in response to changes in membrane lipid composition. Activation involves disruption of an inhibitory interaction between the alphaE helices at the base of the active site and an autoinhibitory (AI) segment in the regulatory M domain and membrane insertion of the M domain as an amphipathic helix. We show that in the CCT soluble form the AI segment functions to suppress kcat and elevate the Km for CTP. The crystal structure of a CCT dimer composed of the catalytic and AI segments reveals an AI-alphaE interaction as a cluster of four amphipathic helices (two alphaE and two AI helices) at the base of the active sites. This interaction corroborates mutagenesis implicating multiple hydrophobic residues within the AI segment that contribute to its silencing function. The AI-alphaE interaction directs the turn at the C-terminal end of the AI helix into backbone-to-backbone contact with a loop (L2) at the opening to the active site, which houses the key catalytic residue, lysine 122. Molecular dynamics simulations suggest that lysine 122 side-chain orientations are constrained by contacts with the AI helix-turn, which could obstruct its engagement with substrates. This work deciphers how the CCT regulatory amphipathic helix functions as a silencing device.
Structural Basis for Autoinhibition of CTP:Phosphocholine Cytidylyltransferase (CCT), the Regulatory Enzyme in Phosphatidylcholine Synthesis, by Its Membrane-binding Amphipathic Helix.,Lee J, Taneva SG, Holland BW, Tieleman DP, Cornell RB J Biol Chem. 2014 Jan 17;289(3):1742-55. doi: 10.1074/jbc.M113.526970. Epub 2013 , Nov 25. PMID:24275660[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Lee J, Taneva SG, Holland BW, Tieleman DP, Cornell RB. Structural Basis for Autoinhibition of CTP:Phosphocholine Cytidylyltransferase (CCT), the Regulatory Enzyme in Phosphatidylcholine Synthesis, by Its Membrane-binding Amphipathic Helix. J Biol Chem. 2014 Jan 17;289(3):1742-55. doi: 10.1074/jbc.M113.526970. Epub 2013 , Nov 25. PMID:24275660 doi:http://dx.doi.org/10.1074/jbc.M113.526970
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