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1wdc
From Proteopedia
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[[Image:1wdc.gif|left|200px]] | [[Image:1wdc.gif|left|200px]] | ||
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'''SCALLOP MYOSIN REGULATORY DOMAIN''' | '''SCALLOP MYOSIN REGULATORY DOMAIN''' | ||
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[[Category: Cohen, C.]] | [[Category: Cohen, C.]] | ||
[[Category: Houdusse, A.]] | [[Category: Houdusse, A.]] | ||
| - | [[Category: | + | [[Category: Calcium binding protein]] |
| - | [[Category: | + | [[Category: Muscle protein]] |
| - | [[Category: | + | [[Category: Myosin]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 13:29:56 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 10:29, 3 May 2008
SCALLOP MYOSIN REGULATORY DOMAIN
Overview
BACKGROUND: In contrast to the myosins of vertebrate skeletal muscle, molluscan myosins are regulated molecules whose enzymatic activity is switched on by the direct binding of Ca2+. The head portion (S1) of the molecule consists of a motor domain and a regulatory domain (RD) containing a 'regulatory' and an 'essential' light chain (RLC and ELC, respectively). The structures of scallop myosin RD with bound Ca2+, as well as the S1 fragment of chicken skeletal muscle myosin, have been determined previously to 2.8 A resolution. RESULTS: We have determined the structure at 2.0 A resolution of scallop myosin RD with bound Ca2+. The unusual coordination at the specific Ca(2+)-binding site in the ELC has now been clarified, as has the structural basis for Mg2+ binding to the RLC. A comparison of the scallop RD structure with that in the chicken S1 structure shows differences in the bending of the two RDs in two different places. CONCLUSIONS: Based on these structural results, a model for regulation is proposed in which the Ca(2+)-bound RD is a rigid structure, and transient flexibility of the Ca(2+)-free RD allows the myosin heads to make stabilizing intramolecular linkage which shut off the motor.
About this Structure
1WDC is a Protein complex structure of sequences from Argopecten irradians. Full crystallographic information is available from OCA.
Reference
Structure of the regulatory domain of scallop myosin at 2 A resolution: implications for regulation., Houdusse A, Cohen C, Structure. 1996 Jan 15;4(1):21-32. PMID:8805510 Page seeded by OCA on Sat May 3 13:29:56 2008
