This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1kql
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1kql.gif|left|200px]] | [[Image:1kql.gif|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1kql", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | | | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), |
| - | | | + | or leave the SCENE parameter empty for the default display. |
| - | + | --> | |
| - | + | {{STRUCTURE_1kql| PDB=1kql | SCENE= }} | |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''Crystal structure of the C-terminal region of striated muscle alpha-tropomyosin at 2.7 angstrom resolution''' | '''Crystal structure of the C-terminal region of striated muscle alpha-tropomyosin at 2.7 angstrom resolution''' | ||
| Line 32: | Line 29: | ||
[[Category: Strand, J.]] | [[Category: Strand, J.]] | ||
[[Category: Tobacman, L S.]] | [[Category: Tobacman, L S.]] | ||
| - | [[Category: | + | [[Category: Coiled coil]] |
| - | [[Category: | + | [[Category: Contractile protein]] |
| - | [[Category: | + | [[Category: Four-helix bundle]] |
| - | [[Category: | + | [[Category: Muscle regulation]] |
| - | [[Category: | + | [[Category: Thin filament]] |
| - | [[Category: | + | [[Category: Tropomyosin]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 23:03:16 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 20:03, 2 May 2008
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 Page seeded by OCA on Fri May 2 23:03:16 2008
