1C2B

ELECTROPHORUS ELECTRICUS ACETYLCHOLINESTERASE

1C2B の概要

• エントリーDOI: 10.2210/pdb1c2b/pdb
• 関連するPDBエントリー: 1C2O 1eea 1maa
• 分子名称: ACETYLCHOLINESTERASE (1 entity in total)
• 機能のキーワード: serine hydrolase, alpha/beta hydrolase, tetramer, hydrolase
• 由来する生物種: Electrophorus electricus (electric eel)
• 細胞内の位置: Cell junction, synapse. Isoform H: Cell membrane; Lipid-anchor, GPI- anchor; Extracellular side: P21836
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 59421.13

構造登録者

Bourne, Y.,Marchot, P. (登録日: 1999-07-26, 公開日: 1999-12-29, 最終更新日: 2021-06-02)

主引用文献

Bourne, Y.,Grassi, J.,Bougis, P.E.,Marchot, P.
Conformational flexibility of the acetylcholinesterase tetramer suggested by x-ray crystallography.
J.Biol.Chem., 274:30370-30376, 1999

PubMed Abstract: 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.

PubMed: 10521413
DOI: 10.1074/jbc.274.43.30370

実験手法

X-RAY DIFFRACTION (4.5 Å)