The aerolysin membrane channel is formed by heptamerization of the monomer.
The cytolytic toxin aerolysin has been found to form heptameric oligomers by SDS-PAGE electrophoresis, STEM mass measurements of single oligomers and image analysis of two-dimensional membrane crystals. Two types of crystal, flat sheets and long regular tubes, have been obtained by reconstitution of purified protein and Escherichia coli phospholipids. A noise-filtered image of the best crystalline sheets reveals a structure with 7-fold symmetry containing a central strongly stain-excluding ring that encircles a dark stain-filled channel 17 A in diameter. The ring is surrounded by seven arms each made up of two unequal sized domains. By combining projected views and side-views, a simplified model of the aerolysin channel complex has been constructed. The relevance of this structure to the mode of action of aerolysin is discussed.
Wilmsen
H U
HU
EMBL, Heidelberg, Germany.
Leonard
K R
KR
Tichelaar
W
W
Buckley
J T
JT
Pattus
F
F
D001427:Bacterial Toxins / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D005583:Fourier Analysis; D007091:Image Processing, Computer-Assisted; D007473:Ion Channels / Q000737:chemistry* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008970:Molecular Weight; D010743:Phospholipids / Q000737:chemistry; D011108:Polymers; D052899:Pore Forming Cytotoxic Proteins; D014357:Trypsin
D001427:Bacterial Toxins; D007473:Ion Channels; D010743:Phospholipids; D011108:Polymers; D052899:Pore Forming Cytotoxic Proteins; C032676:aerolysin; D014357:Trypsin