View source for 3pdt


==Crystal Structure of the C-terminal Truncated Alpha-Kinase Domain of Myosin Heavy chain Kinase==
<StructureSection load='3pdt' size='340' side='right'caption='[[3pdt]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3pdt]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Dictyostelium_discoideum Dictyostelium discoideum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3PDT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3PDT 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]] 1.8&#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=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=3pdt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3pdt OCA], [https://pdbe.org/3pdt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3pdt RCSB], [https://www.ebi.ac.uk/pdbsum/3pdt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3pdt ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MHCKA_DICDI MHCKA_DICDI] Phosphorylates threonine in the C-terminal tail region of myosin II heavy chain. This phosphorylation is critical in regulating the assembly and disassembly of myosin II filament. Requires autophosphorylation for activity.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Dictyostelium discoideum myosin II heavy chain kinase A (MHCK A), a member of the atypical alpha-kinase family, phosphorylates sites in the myosin II tail that block filament assembly. Here we show that the catalytic activity of A-CAT, the alpha-kinase domain of MHCK A (residues 552-841), is severely inhibited by the removal of a disordered C-terminal tail sequence (C-tail; residues 806-841). The key residue in the C-tail was identified as Thr825, which was found to be constitutively autophosphorylated. Dephosphorylation of Thr825 using shrimp alkaline phosphatase decreased A-CAT activity. The activity of a truncated ACAT lacking Thr825 could be rescued by Pi, phosphothreonine and a phosphorylated peptide, but not by threonine, glutamic acid, aspartic acid or an unphosphorylated peptide. These results focused attention on a Pi-binding pocket located in the C-terminal lobe of A-CAT. Mutational analysis demonstrated that the Pi-pocket was essential for A-CAT activity. Based on these results, it is proposed that autophosphorylation of Thr825 activates ACAT by providing a covalently-tethered ligand for the Pi-pocket. Ab initio modeling studies using the Rosetta FloppyTail and FlexPepDock protocols showed that it is feasible for the phosphorylated Thr825 to dock intramolecularly into the Pi-pocket. Allosteric activation is predicted to involve a conformational change in Arg734, which bridges the bound Pi to Asp762 in a key active site loop. Sequence alignments indicate that a comparable regulatory mechanism is likely to be conserved in Dictyostelium MHCK B-D and metazoan eukaryotic elongation factor-2 kinases.

Autophosphorylation activates Dictyostelium myosin II heavy chain kinase A by providing a ligand for an allosteric binding site in the {alpha}-kinase domain.,Crawley SW, Samimi Gharaei M, Ye Q, Yang Y, Raveh B, London N, Schueler-Furman O, Jia Z, Cote GP J Biol Chem. 2010 Nov 11. PMID:21071445<ref>PMID:21071445</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3pdt" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Dictyostelium discoideum]]
[[Category: Large Structures]]
[[Category: Jia Z]]
[[Category: Ye Q]]