2w4u: Difference between revisions
No edit summary |
No edit summary |
||
| (14 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
The | ==Isometrically contracting insect asynchronous flight muscle quick frozen after a length step== | ||
<SX load='2w4u' size='340' side='right' viewer='molstar' caption='[[2w4u]], [[Resolution|resolution]] 35.00Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2w4u]] is a 36 chain structure with sequence from [https://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] and [https://en.wikipedia.org/wiki/Oryctolagus_cuniculus Oryctolagus cuniculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2W4U OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2W4U 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]] 35Å</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=2w4u FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2w4u OCA], [https://pdbe.org/2w4u PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2w4u RCSB], [https://www.ebi.ac.uk/pdbsum/2w4u PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2w4u ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/TNNC2_CHICK TNNC2_CHICK] Troponin is the central regulatory protein of striated muscle contraction. Tn consists of three components: Tn-I which is the inhibitor of actomyosin ATPase, Tn-T which contains the binding site for tropomyosin and Tn-C. The binding of calcium to Tn-C abolishes the inhibitory action of Tn on actin filaments. | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/w4/2w4u_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2w4u ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The application of rapidly applied length steps to actively contracting muscle is a classic method for synchronizing the response of myosin cross-bridges so that the average response of the ensemble can be measured. Alternatively, electron tomography (ET) is a technique that can report the structure of the individual members of the ensemble. We probed the structure of active myosin motors (cross-bridges) by applying 0.5% changes in length (either a stretch or a release) within 2 ms to isometrically contracting insect flight muscle (IFM) fibers followed after 5-6 ms by rapid freezing against a liquid helium cooled copper mirror. ET of freeze-substituted fibers, embedded and thin-sectioned, provides 3-D cross-bridge images, sorted by multivariate data analysis into approximately 40 classes, distinct in average structure, population size and lattice distribution. Individual actin subunits are resolved facilitating quasi-atomic modeling of each class average to determine its binding strength (weak or strong) to actin. approximately 98% of strong-binding acto-myosin attachments present after a length perturbation are confined to "target zones" of only two actin subunits located exactly midway between successive troponin complexes along each long-pitch helical repeat of actin. Significant changes in the types, distribution and structure of actin-myosin attachments occurred in a manner consistent with the mechanical transients. Most dramatic is near disappearance, after either length perturbation, of a class of weak-binding cross-bridges, attached within the target zone, that are highly likely to be precursors of strong-binding cross-bridges. These weak-binding cross-bridges were originally observed in isometrically contracting IFM. Their disappearance following a quick stretch or release can be explained by a recent kinetic model for muscle contraction, as behaviour consistent with their identification as precursors of strong-binding cross-bridges. The results provide a detailed model for contraction in IFM that may be applicable to contraction in other types of muscle. | |||
Structural Changes in Isometrically Contracting Insect Flight Muscle Trapped following a Mechanical Perturbation.,Wu S, Liu J, Reedy MC, Perz-Edwards RJ, Tregear RT, Winkler H, Franzini-Armstrong C, Sasaki H, Lucaveche C, Goldman YE, Reedy MK, Taylor KA PLoS One. 2012;7(6):e39422. Epub 2012 Jun 25. PMID:22761792<ref>PMID:22761792</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 2w4u" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Tropomyosin 3D structures|Tropomyosin 3D structures]] | |||
*[[Troponin 3D structures|Troponin 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</SX> | |||
[[Category: Gallus gallus]] | |||
[[Category: Large Structures]] | |||
[[Category: Oryctolagus cuniculus]] | |||
[[Category: Franzini-Armstrong C]] | |||
[[Category: Goldman YE]] | |||
[[Category: Liu J]] | |||
[[Category: Lucaveche C]] | |||
[[Category: Reedy MC]] | |||
[[Category: Reedy MK]] | |||
[[Category: Sasaki H]] | |||
[[Category: Taylor KA]] | |||
[[Category: Tregear RT]] | |||
[[Category: Winkler H]] | |||
[[Category: Wu S]] | |||