1c2b

<StructureSection load='1c2b' size='340' side='right' caption='[[1c2b]], [[Resolution|resolution]] 4.50&Aring;' scene=''>

<table><tr><td colspan='2'>[[1c2b]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Electrophorus_electricus Electrophorus electricus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1C2B OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1C2B FirstGlance]. <br>

</td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1eea|1eea]], [[1c2o|1c2o]], [[1maa|1maa]]</td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Acetylcholinesterase Acetylcholinesterase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.7 3.1.1.7] </span></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=1c2b FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1c2b OCA], [http://pdbe.org/1c2b PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1c2b RCSB], [http://www.ebi.ac.uk/pdbsum/1c2b PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1c2b ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/ACES_MOUSE ACES_MOUSE]] Terminates signal transduction at the neuromuscular junction by rapid hydrolysis of the acetylcholine released into the synaptic cleft.

<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/c2/1c2b_consurf.spt"</scriptWhenChecked>

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== Publication Abstract from PubMed ==

Acetylcholinesterase, a polymorphic enzyme, appears to form amphiphilic and nonamphiphilic tetramers from a single splice variant; this suggests discrete tetrameric arrangements where the amphipathic carboxyl-terminal sequences can be either buried or exposed. Two distinct, but related crystal structures of the soluble, trypsin-released tetramer of acetylcholinesterase from Electrophorus electricus were solved at 4.5 and 4.2 A resolution by molecular replacement. Resolution at these levels is sufficient to provide substantial information on the relative orientations of the subunits within the tetramer. The two structures, which show canonical homodimers of subunits assembled through four-helix bundles, reveal discrete geometries in the assembly of the dimers to form: (a) a loose, pseudo-square planar tetramer with antiparallel alignment of the two four-helix bundles and a large space in the center where the carboxyl-terminal sequences may be buried or (b) a compact, square nonplanar tetramer that may expose all four sequences on a single side. Comparison of these two structures points to significant conformational flexibility of the tetramer about the four-helix bundle axis and along the dimer-dimer interface. Hence, in solution, several conformational states of a flexible tetrameric arrangement of acetylcholinesterase catalytic subunits may exist to accommodate discrete carboxyl-terminal sequences of variable dimensions and amphipathicity.

Conformational flexibility of the acetylcholinesterase tetramer suggested by x-ray crystallography.,Bourne Y, Grassi J, Bougis PE, Marchot P J Biol Chem. 1999 Oct 22;274(43):30370-6. PMID:10521413<ref>PMID:10521413</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 1c2b" style="background-color:#fffaf0;"></div>

*[[3D structures of acetylcholinesterase|3D structures of acetylcholinesterase]]

== References ==

<references/>

[[Category: Acetylcholinesterase]]

[[Category: Bourne, Y]]

[[Category: Marchot, P]]

[[Category: Alpha/beta hydrolase]]

[[Category: Tetramer]]