1sr6: Difference between revisions

Revision as of 09:03, 3 May 2008

Structure of nucleotide-free scallop myosin S1

OverviewOverview

Structural studies of myosin have indicated some of the conformational changes that occur in this protein during the contractile cycle, and we have now observed a conformational change in a bound nucleotide as well. The 3.1-A x-ray structure of the scallop myosin head domain (subfragment 1) in the ADP-bound near-rigor state (lever arm =45 degrees to the helical actin axis) shows the diphosphate moiety positioned on the surface of the nucleotide-binding pocket, rather than deep within it as had been observed previously. This conformation strongly suggests a specific mode of entry and exit of the nucleotide from the nucleotide-binding pocket through the so-called "front door." In addition, using a variety of scallop structures, including a relatively high-resolution 2.75-A nucleotide-free near-rigor structure, we have identified a conserved complex salt bridge connecting the 50-kDa upper and N-terminal subdomains. This salt bridge is present only in crystal structures of muscle myosin isoforms that exhibit a strong reciprocal relationship (also known as coupling) between actin and nucleotide affinity.

About this StructureAbout this Structure

1SR6 is a Protein complex structure of sequences from Argopecten irradians. Full crystallographic information is available from OCA.

ReferenceReference

Myosin subfragment 1 structures reveal a partially bound nucleotide and a complex salt bridge that helps couple nucleotide and actin binding., Risal D, Gourinath S, Himmel DM, Szent-Gyorgyi AG, Cohen C, Proc Natl Acad Sci U S A. 2004 Jun 15;101(24):8930-5. Epub 2004 Jun 7. PMID:15184651 Page seeded by OCA on Sat May 3 09:03:02 2008

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OCA

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 [[Image:1sr6.gif|left|200px]]
- {{Structure
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-|RELATEDENTRY=[[1s5g|1S5G]], [[1qvi|1QVI]], [[1kk8|1KK8]]
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1sr6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1sr6 OCA], [http://www.ebi.ac.uk/pdbsum/1sr6 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1sr6 RCSB]</span>
-}}
 '''Structure of nucleotide-free scallop myosin S1'''
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 [[Category: Risal, D.]]
 [[Category: Szent-Gyorgyi, A G.]]
-[[Category: complex salt bridge]]
+[[Category: Complex salt bridge]]
-[[Category: near rigor]]
+[[Category: Near rigor]]
-[[Category: novel conformation of nucleotide]]
+[[Category: Novel conformation of nucleotide]]
-[[Category: scallop myosin s1]]
+[[Category: Scallop myosin s1]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 09:03:02 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:45:54 2008''