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2w4t

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Revision as of 07:15, 23 October 2019

ISOMETRICALLY CONTRACTING INSECT ASYNCHRONOUS FLIGHT MUSCLE

Structural highlights

2w4t is a 3 chain structure with sequence from Argopecten irradians. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Related:	1sr6, 1s5g, 1qvi, 2w4w, 1kqm, 1kwo, 1scm, 1dfl, 1b7t, 2w4v, 1kk7, 1wdc, 1l2o, 1dfk, 1kk8
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[MYS_ARGIR] Muscle contraction. Myosin is a protein that binds to F-actin and has ATPase activity that is activated by F-actin. [MLE_ARGIR] In molluscan muscle, calcium regulation is associated with myosin rather than with actin. Muscle myosin contains two types of light chains: the catalytic light chain, essential for ATPase activity, and the regulatory light chain, a calcium-binding protein responsible for Ca(2+) dependent binding and Ca(2+) dependent Mg-ATPase activity. [MLR_ARGIR] In molluscan muscle, calcium regulation is associated with myosin rather than with actin. Muscle myosin contains two types of light chains: the catalytic light chain, essential for ATPase activity, and the regulatory light chain, a calcium-binding protein responsible for Ca(2+) dependent binding and Ca(2+) dependent Mg-ATPase activity.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

BACKGROUND: Isometric muscle contraction, where force is generated without muscle shortening, is a molecular traffic jam in which the number of actin-attached motors is maximized and all states of motor action are trapped with consequently high heterogeneity. This heterogeneity is a major limitation to deciphering myosin conformational changes in situ. METHODOLOGY: We used multivariate data analysis to group repeat segments in electron tomograms of isometrically contracting insect flight muscle, mechanically monitored, rapidly frozen, freeze substituted, and thin sectioned. Improved resolution reveals the helical arrangement of F-actin subunits in the thin filament enabling an atomic model to be built into the thin filament density independent of the myosin. Actin-myosin attachments can now be assigned as weak or strong by their motor domain orientation relative to actin. Myosin attachments were quantified everywhere along the thin filament including troponin. Strong binding myosin attachments are found on only four F-actin subunits, the "target zone", situated exactly midway between successive troponin complexes. They show an axial lever arm range of 77 degrees /12.9 nm. The lever arm azimuthal range of strong binding attachments has a highly skewed, 127 degrees range compared with X-ray crystallographic structures. Two types of weak actin attachments are described. One type, found exclusively in the target zone, appears to represent pre-working-stroke intermediates. The other, which contacts tropomyosin rather than actin, is positioned M-ward of the target zone, i.e. the position toward which thin filaments slide during shortening. CONCLUSION: We present a model for the weak to strong transition in the myosin ATPase cycle that incorporates azimuthal movements of the motor domain on actin. Stress/strain in the S2 domain may explain azimuthal lever arm changes in the strong binding attachments. The results support previous conclusions that the weak attachments preceding force generation are very different from strong binding attachments.

Electron tomography of cryofixed, isometrically contracting insect flight muscle reveals novel actin-myosin interactions.,Wu S, Liu J, Reedy MC, Tregear RT, Winkler H, Franzini-Armstrong C, Sasaki H, Lucaveche C, Goldman YE, Reedy MK, Taylor KA PLoS One. 2010 Sep 9;5(9). pii: e12643. PMID:20844746^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Wu S, Liu J, Reedy MC, Tregear RT, Winkler H, Franzini-Armstrong C, Sasaki H, Lucaveche C, Goldman YE, Reedy MK, Taylor KA. Electron tomography of cryofixed, isometrically contracting insect flight muscle reveals novel actin-myosin interactions. PLoS One. 2010 Sep 9;5(9). pii: e12643. PMID:20844746 doi:10.1371/journal.pone.0012643

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 See Also
6 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/2w4t"

@@ Line 1: / Line 1: @@
-{{Large structure}}
 ==ISOMETRICALLY CONTRACTING INSECT ASYNCHRONOUS FLIGHT MUSCLE==
-<StructureSection load='2w4t' size='340' side='right' caption='[[2w4t]], [[Resolution|resolution]] 35.00&Aring;' scene=''>
+<StructureSection load='2w4t' size='340' side='right'caption='[[2w4t]], [[Resolution|resolution]] 35.00&Aring;' scene=''>
 == Structural highlights ==
 <table><tr><td colspan='2'>[[2w4t]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Argopecten_irradians Argopecten irradians]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2W4T OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2W4T FirstGlance]. <br>
@@ Line 7: / Line 7: @@
 <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=2w4t FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2w4t OCA], [http://pdbe.org/2w4t PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2w4t RCSB], [http://www.ebi.ac.uk/pdbsum/2w4t PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2w4t ProSAT]</span></td></tr>
 </table>
-{{Large structure}}
 == Function ==
 [[http://www.uniprot.org/uniprot/MYS_ARGIR MYS_ARGIR]] Muscle contraction.  Myosin is a protein that binds to F-actin and has ATPase activity that is activated by F-actin. [[http://www.uniprot.org/uniprot/MLE_ARGIR MLE_ARGIR]] In molluscan muscle, calcium regulation is associated with myosin rather than with actin. Muscle myosin contains two types of light chains: the catalytic light chain, essential for ATPase activity, and the regulatory light chain, a calcium-binding protein responsible for Ca(2+) dependent binding and Ca(2+) dependent Mg-ATPase activity. [[http://www.uniprot.org/uniprot/MLR_ARGIR MLR_ARGIR]] In molluscan muscle, calcium regulation is associated with myosin rather than with actin. Muscle myosin contains two types of light chains: the catalytic light chain, essential for ATPase activity, and the regulatory light chain, a calcium-binding protein responsible for Ca(2+) dependent binding and Ca(2+) dependent Mg-ATPase activity.
@@ Line 37: / Line 36: @@
 </StructureSection>
 [[Category: Argopecten irradians]]
+[[Category: Large Structures]]
 [[Category: Franzini-Armstrong, C]]
 [[Category: Goldman, Y E]]

2w4t

From Proteopedia

Revision as of 07:15, 23 October 2019

ISOMETRICALLY CONTRACTING INSECT ASYNCHRONOUS FLIGHT MUSCLE

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

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