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1sr6
From Proteopedia
(New page: 200px<br /><applet load="1sr6" size="450" color="white" frame="true" align="right" spinBox="true" caption="1sr6, resolution 2.75Å" /> '''Structure of nucleot...) |
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| - | [[Image:1sr6.gif|left|200px]]<br /><applet load="1sr6" size=" | + | [[Image:1sr6.gif|left|200px]]<br /><applet load="1sr6" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1sr6, resolution 2.75Å" /> | caption="1sr6, resolution 2.75Å" /> | ||
'''Structure of nucleotide-free scallop myosin S1'''<br /> | '''Structure of nucleotide-free scallop myosin S1'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Structural studies of myosin have indicated some of the conformational | + | 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== | ==About this Structure== | ||
| - | 1SR6 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Argopecten_irradians Argopecten irradians] with SO4, MG and CA as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1SR6 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Argopecten_irradians Argopecten irradians] with <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SR6 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Cohen, C.]] | [[Category: Cohen, C.]] | ||
[[Category: Gourinath, S.]] | [[Category: Gourinath, S.]] | ||
| - | [[Category: Himmel, D | + | [[Category: Himmel, D M.]] |
[[Category: Risal, D.]] | [[Category: Risal, D.]] | ||
| - | [[Category: Szent-Gyorgyi, A | + | [[Category: Szent-Gyorgyi, A G.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: MG]] | [[Category: MG]] | ||
| Line 26: | Line 26: | ||
[[Category: scallop myosin s1]] | [[Category: scallop myosin s1]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:04:21 2008'' |
Revision as of 13:04, 21 February 2008
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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 with , and as ligands. 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 Thu Feb 21 15:04:21 2008
