1c2b: Difference between revisions
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|ACTIVITY= [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] | |ACTIVITY= <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> | ||
|GENE= | |GENE= | ||
|DOMAIN= | |||
|RELATEDENTRY=[[1eea|1EEA]], [[1c2o|1C2O]], [[1maa|1MAA]] | |||
|RESOURCES=<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://www.ebi.ac.uk/pdbsum/1c2b PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1c2b RCSB]</span> | |||
}} | }} | ||
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[[Category: tetramer]] | [[Category: tetramer]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 19:13:07 2008'' | ||
Revision as of 19:13, 30 March 2008
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| , resolution 4.5Å | |||||||
|---|---|---|---|---|---|---|---|
| Activity: | Acetylcholinesterase, with EC number 3.1.1.7 | ||||||
| Related: | 1EEA, 1C2O, 1MAA
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
ELECTROPHORUS ELECTRICUS ACETYLCHOLINESTERASE
OverviewOverview
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.
About this StructureAbout this Structure
1C2B is a Single protein structure of sequence from Electrophorus electricus. Full crystallographic information is available from OCA.
ReferenceReference
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
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