Structure of Staphylococcal α-Hemolysin, a Heptameric Transmembrane Pore
Abstract
The structure of the Staphylococcus aureus α-hemolysin pore has been determined to 1.9 overset{circ}{mathrm A} resolution. Contained within the mushroom-shaped homo-oligomeric heptamer is a solvent-filled channel, 100 overset{circ}{mathrm A} in length, that runs along the sevenfold axis and ranges from 14 overset{circ}{mathrm A} to 46 overset{circ}{mathrm A} in diameter. The lytic, transmembrane domain comprises the lower half of a 14-strand antiparallel β barrel, to which each protomer contributes two β strands, each 65 overset{circ}{mathrm A} long. The interior of the β barrel is primarily hydrophilic, and the exterior has a hydrophobic belt 28 overset{circ}{mathrm A} wide. The structure proves the heptameric subunit stoichiometry of the α-hemolysin oligomer, shows that a glycine-rich and solvent-exposed region of a water-soluble protein can self-assemble to form a transmembrane pore of defined structure, and provides insight into the principles of membrane interaction and transport activity of β barrel pore-forming toxins.
- Publication:
-
Science
- Pub Date:
- December 1996
- DOI:
- 10.1126/science.274.5294.1859
- Bibcode:
- 1996Sci...274.1859S