1ic2

<table><tr><td colspan='2'>[[1ic2]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Chick Chick]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IC2 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1IC2 FirstGlance]. <br>

</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ic2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ic2 OCA], [http://pdbe.org/1ic2 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1ic2 RCSB], [http://www.ebi.ac.uk/pdbsum/1ic2 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1ic2 ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/TPM1_CHICK TPM1_CHICK]] Binds to actin filaments in muscle and non-muscle cells. Plays a central role, in association with the troponin complex, in the calcium dependent regulation of vertebrate striated muscle contraction. Smooth muscle contraction is regulated by interaction with caldesmon. In non-muscle cells is implicated in stabilizing cytoskeleton actin filaments.

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== Publication Abstract from PubMed ==

The crystal structure at 2.0-A resolution of an 81-residue N-terminal fragment of muscle alpha-tropomyosin reveals a parallel two-stranded alpha-helical coiled-coil structure with a remarkable core. The high alanine content of the molecule is clustered into short regions where the local 2-fold symmetry is broken by a small (approximately 1.2-A) axial staggering of the helices. The joining of these regions with neighboring segments, where the helices are in axial register, gives rise to specific bends in the molecular axis. We observe such bends to be widely distributed in two-stranded alpha-helical coiled-coil proteins. This asymmetric design in a dimer of identical (or highly similar) sequences allows the tropomyosin molecule to adopt multiple bent conformations. The seven alanine clusters in the core of the complete molecule (which spans seven monomers of the actin helix) promote the semiflexible winding of the tropomyosin filament necessary for its regulatory role in muscle contraction.

Deciphering the design of the tropomyosin molecule.,Brown JH, Kim KH, Jun G, Greenfield NJ, Dominguez R, Volkmann N, Hitchcock-DeGregori SE, Cohen C Proc Natl Acad Sci U S A. 2001 Jul 17;98(15):8496-501. Epub 2001 Jul 3. PMID:11438684<ref>PMID:11438684</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 1ic2" style="background-color:#fffaf0;"></div>

*[[Tropomyosin|Tropomyosin]]

[[Category: Chick]]

[[Category: Brown, J H]]

[[Category: Cohen, C]]

[[Category: Dominguez, R]]

[[Category: Greenfield, N J]]

[[Category: Hitchcock-DeGregori, S E]]

[[Category: Jun, G]]

[[Category: Kim, K H]]

[[Category: Volkmann, N]]

[[Category: Symmetry]]