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1sr6
From Proteopedia
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[[Image:1sr6.gif|left|200px]] | [[Image:1sr6.gif|left|200px]] | ||
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'''Structure of nucleotide-free scallop myosin S1''' | '''Structure of nucleotide-free scallop myosin S1''' | ||
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[[Category: Risal, D.]] | [[Category: Risal, D.]] | ||
[[Category: Szent-Gyorgyi, A G.]] | [[Category: Szent-Gyorgyi, A G.]] | ||
| - | [[Category: | + | [[Category: Complex salt bridge]] |
| - | [[Category: | + | [[Category: Near rigor]] |
| - | [[Category: | + | [[Category: Novel conformation of nucleotide]] |
| - | [[Category: | + | [[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 | + | |
Revision as of 06:03, 3 May 2008
Structure of nucleotide-free scallop myosin S1
Overview
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 Structure
1SR6 is a Protein complex structure of sequences from Argopecten irradians. Full crystallographic information is available from OCA.
Reference
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
