View source for 5mva


==Structure of the thin filament at high calcium concentration==
<SX load='5mva' size='340' side='right' viewer='molstar' caption='[[5mva]], [[Resolution|resolution]] 27.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5mva]] is a 23 chain structure with sequence from [https://en.wikipedia.org/wiki/Oryctolagus_cuniculus Oryctolagus cuniculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5MVA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5MVA FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 27.7&#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=HIC:4-METHYL-HISTIDINE'>HIC</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=5mva FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5mva OCA], [https://pdbe.org/5mva PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5mva RCSB], [https://www.ebi.ac.uk/pdbsum/5mva PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5mva ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ACTS_RABIT ACTS_RABIT] Actins are highly conserved proteins that are involved in various types of cell motility and are ubiquitously expressed in all eukaryotic cells.
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== Publication Abstract from PubMed ==
The structures of muscle thin filaments reconstituted using skeletal actin and cardiac troponin and tropomyosin have been determined with and without bound Ca(2+) using electron microscopy and reference-free single particle analysis. The resulting density maps have been fitted with atomic models of actin, tropomyosin and troponin showing that: (i) the polarity of the troponin complex is consistent with our 2009 findings, with large shape changes in troponin between the two states; (ii) without Ca(2+) the tropomyosin pseudo-repeats all lie at almost equivalent positions in the 'blocked' position on actin (over subdomains 1 and 2); (iii) in the active state the tropomyosin pseudo-repeats are all displaced towards subdomains 3 and 4 of actin, but the extent of displacement varies within the regulatory unit depending upon the axial location of the pseudo-repeats with respect to troponin. Individual pseudo-repeats with Ca(2+) bound to troponin can be assigned either to the 'closed' state, a partly activated conformation, or the 'M-state', a fully activated conformation which has previously been thought to occur only when myosin heads bind. These results lead to a modified view of the steric blocking model of thin filament regulation in which cooperative activation is governed by troponin-mediated local interactions of the pseudo-repeats of tropomyosin with actin.

Relaxed and active thin filament structures; a new structural basis for the regulatory mechanism.,Paul DM, Squire JM, Morris EP J Struct Biol. 2017 Mar;197(3):365-371. doi: 10.1016/j.jsb.2017.01.004. Epub 2017, Feb 1. PMID:28161413<ref>PMID:28161413</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 5mva" style="background-color:#fffaf0;"></div>

==See Also==
*[[Actin 3D structures|Actin 3D structures]]
== References ==
<references/>
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[[Category: Large Structures]]
[[Category: Oryctolagus cuniculus]]
[[Category: Morris EP]]
[[Category: Paul DM]]
[[Category: Squire JM]]