Structure of staphylococcal alpha-hemolysin, a heptameric transmembrane pore.
The structure of the Staphylococcus aureus alpha-hemolysin pore has been determined to 1.9 A resolution. Contained within the mushroom-shaped homo-oligomeric heptamer is a solvent-filled channel, 100 A in length, that runs along the sevenfold axis and ranges from 14 A to 46 A in diameter. The lytic, transmembrane domain comprises the lower half of a 14-strand antiparallel beta barrel, to which each protomer contributes two beta strands, each 65 A long. The interior of the beta barrel is primarily hydrophilic, and the exterior has a hydrophobic belt 28 A wide. The structure proves the heptameric subunit stoichiometry of the alpha-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 beta barrel pore-forming toxins.
Song
L
L
Department of Biochemistry, University of Chicago, 920 East 58 Street, Chicago, IL 60637, USA.
Hobaugh
M R
MR
Shustak
C
C
Cheley
S
S
Bayley
H
H
Gouaux
J E
JE
D000595:Amino Acid Sequence; D001427:Bacterial Toxins / Q000737:chemistry* / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D018360:Crystallography, X-Ray; D006460:Hemolysin Proteins / Q000737:chemistry* / Q000378:metabolism; D006860:Hydrogen Bonding; D008051:Lipid Bilayers / Q000737:chemistry*; D008564:Membrane Potentials; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D013211:Staphylococcus aureus / Q000737:chemistry*
D001427:Bacterial Toxins; D006460:Hemolysin Proteins; D008051:Lipid Bilayers; C021091:staphylococcal alpha-toxin