View source for 3feg


==Crystal structure of human choline kinase beta in complex with phosphorylated hemicholinium-3 and adenosine nucleotide==
<StructureSection load='3feg' size='340' side='right'caption='[[3feg]], [[Resolution|resolution]] 1.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3feg]] is a 1 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=3FEG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3FEG 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]] 1.302&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ADP:ADENOSINE-5-DIPHOSPHATE'>ADP</scene>, <scene name='pdbligand=AMP:ADENOSINE+MONOPHOSPHATE'>AMP</scene>, <scene name='pdbligand=HC7:(2S)-2-[4-({DIMETHYL[2-(PHOSPHONOOXY)ETHYL]AMMONIO}ACETYL)BIPHENYL-4-YL]-2-HYDROXY-4,4-DIMETHYLMORPHOLIN-4-IUM'>HC7</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=UNX:UNKNOWN+ATOM+OR+ION'>UNX</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=3feg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3feg OCA], [https://pdbe.org/3feg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3feg RCSB], [https://www.ebi.ac.uk/pdbsum/3feg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3feg ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CHKB_HUMAN CHKB_HUMAN] Has a key role in phospholipid biosynthesis. Catalyzes the first step in phosphatidylethanolamine biosynthesis. Phosphorylates ethanolamine, and can also act on choline (in vitro). Has higher activity with ethanolamine. May not significantly contribute to in vivo phosphatidylcholine biosynthesis.<ref>PMID:19915674</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Human choline kinase (ChoK) catalyzes the first reaction in phosphatidylcholine biosynthesis and exists as ChoKalpha (alpha1 and alpha2) and ChoKbeta isoforms. Recent studies suggest that ChoK is implicated in tumorigenesis and emerging as an attractive target for anticancer chemotherapy. To extend our understanding of the molecular mechanism of ChoK inhibition, we have determined the high resolution x-ray structures of the ChoKalpha1 and ChoKbeta isoforms in complex with hemicholinium-3 (HC-3), a known inhibitor of ChoK. In both structures, HC-3 bound at the conserved hydrophobic groove on the C-terminal lobe. One of the HC-3 oxazinium rings complexed with ChoKalpha1 occupied the choline-binding pocket, providing a structural explanation for its inhibitory action. Interestingly, the HC-3 molecule co-crystallized with ChoKbeta was phosphorylated in the choline binding site. This phosphorylation, albeit occurring at a very slow rate, was confirmed experimentally by mass spectroscopy and radioactive assays. Detailed kinetic studies revealed that HC-3 is a much more potent inhibitor for ChoKalpha isoforms (alpha1 and alpha2) compared with ChoKbeta. Mutational studies based on the structures of both inhibitor-bound ChoK complexes demonstrated that Leu-401 of ChoKalpha2 (equivalent to Leu-419 of ChoKalpha1), or the corresponding residue Phe-352 of ChoKbeta, which is one of the hydrophobic residues neighboring the active site, influences the plasticity of the HC-3-binding groove, thereby playing a key role in HC-3 sensitivity and phosphorylation.

Crystal structures of human choline kinase isoforms in complex with hemicholinium-3: single amino acid near the active site influences inhibitor sensitivity.,Hong BS, Allali-Hassani A, Tempel W, Finerty PJ Jr, Mackenzie F, Dimov S, Vedadi M, Park HW J Biol Chem. 2010 May 21;285(21):16330-40. Epub 2010 Mar 18. PMID:20299452<ref>PMID:20299452</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3feg" style="background-color:#fffaf0;"></div>

==See Also==
*[[Choline kinase 3D structures|Choline kinase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Arrowsmith CH]]
[[Category: Bochkarev A]]
[[Category: Bountra C]]
[[Category: Edwards AM]]
[[Category: Hong BS]]
[[Category: MacKenzie F]]
[[Category: Park HW]]
[[Category: Rabeh WM]]
[[Category: Tempel W]]
[[Category: Weigelt J]]