1kql
From Proteopedia
(New page: 200px<br /><applet load="1kql" size="450" color="white" frame="true" align="right" spinBox="true" caption="1kql, resolution 2.70Å" /> '''Crystal structure of...) |
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| - | [[Image:1kql.gif|left|200px]]<br /><applet load="1kql" size=" | + | [[Image:1kql.gif|left|200px]]<br /><applet load="1kql" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1kql, resolution 2.70Å" /> | caption="1kql, resolution 2.70Å" /> | ||
'''Crystal structure of the C-terminal region of striated muscle alpha-tropomyosin at 2.7 angstrom resolution'''<br /> | '''Crystal structure of the C-terminal region of striated muscle alpha-tropomyosin at 2.7 angstrom resolution'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Contraction in striated and cardiac muscles is regulated by the motions of | + | Contraction in striated and cardiac muscles is regulated by the motions of a Ca(2+)-sensitive tropomyosin/troponin switch. In contrast, troponin is absent in other muscle types and in nonmuscle cells, and actomyosin regulation is myosin-linked. Here we report an unusual crystal structure at 2.7 A of the C-terminal 31 residues of rat striated-muscle alpha-tropomyosin (preceded by a fragment of the GCN4 leucine zipper). The C-terminal 22 residues (263-284) of the structure do not form a two-stranded alpha-helical coiled coil as does the rest of the molecule, but here the alpha-helices splay apart and are stabilized by the formation of a tail-to-tail dimer with a symmetry-related molecule. The site of splaying involves a small group of destabilizing core residues that is present only in striated muscle tropomyosin isoforms. These results reveal a specific recognition site for troponin T and clarify the physical basis for the unique regulatory mechanism of striated muscles. |
==About this Structure== | ==About this Structure== | ||
| - | 1KQL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae_and_rattus_norvegicus Saccharomyces cerevisiae and rattus norvegicus]. Full crystallographic information is available from [http:// | + | 1KQL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae_and_rattus_norvegicus Saccharomyces cerevisiae and rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KQL OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Saccharomyces cerevisiae and rattus norvegicus]] | [[Category: Saccharomyces cerevisiae and rattus norvegicus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Brown, J | + | [[Category: Brown, J H.]] |
[[Category: Cohen, C.]] | [[Category: Cohen, C.]] | ||
[[Category: Li, Y.]] | [[Category: Li, Y.]] | ||
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[[Category: Reshetnikova, L.]] | [[Category: Reshetnikova, L.]] | ||
[[Category: Strand, J.]] | [[Category: Strand, J.]] | ||
| - | [[Category: Tobacman, L | + | [[Category: Tobacman, L S.]] |
[[Category: coiled coil]] | [[Category: coiled coil]] | ||
[[Category: contractile protein]] | [[Category: contractile protein]] | ||
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[[Category: tropomyosin]] | [[Category: tropomyosin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:36:56 2008'' |
Revision as of 11:36, 21 February 2008
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Crystal structure of the C-terminal region of striated muscle alpha-tropomyosin at 2.7 angstrom resolution
Overview
Contraction in striated and cardiac muscles is regulated by the motions of a Ca(2+)-sensitive tropomyosin/troponin switch. In contrast, troponin is absent in other muscle types and in nonmuscle cells, and actomyosin regulation is myosin-linked. Here we report an unusual crystal structure at 2.7 A of the C-terminal 31 residues of rat striated-muscle alpha-tropomyosin (preceded by a fragment of the GCN4 leucine zipper). The C-terminal 22 residues (263-284) of the structure do not form a two-stranded alpha-helical coiled coil as does the rest of the molecule, but here the alpha-helices splay apart and are stabilized by the formation of a tail-to-tail dimer with a symmetry-related molecule. The site of splaying involves a small group of destabilizing core residues that is present only in striated muscle tropomyosin isoforms. These results reveal a specific recognition site for troponin T and clarify the physical basis for the unique regulatory mechanism of striated muscles.
About this Structure
1KQL is a Single protein structure of sequence from Saccharomyces cerevisiae and rattus norvegicus. Full crystallographic information is available from OCA.
Reference
The crystal structure of the C-terminal fragment of striated-muscle alpha-tropomyosin reveals a key troponin T recognition site., Li Y, Mui S, Brown JH, Strand J, Reshetnikova L, Tobacman LS, Cohen C, Proc Natl Acad Sci U S A. 2002 May 28;99(11):7378-83. PMID:12032291
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