Abstract
LukF and Hlg2 of staphylococcal gamma-hemolysin assemble into hetero-oligomeric pores on human red blood cells (HRBC). Here, we demonstrate, using a single-molecule imaging technique, that a W177T/R198T mutant of LukF, which exhibits no binding activity toward phosphatidylcholine, could form intermediate oligomers with Hlg2, including dimers, tetramers, and hexamer/heptamers, on HRBC. But, the mutant neither caused K(+) efflux nor lysed HRBC, indicating that functional pores were not formed. Hence, we conclude that the W177 and R198 residues are essential for proper pore-formation by staphylococcal gamma-hemolysin. We also suggest that the interaction between the W177 and R198 residues, and phosphatidylcholine on membranes is the key to the formation of functional pores.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Arginine / chemistry
-
Bacterial Proteins / chemistry*
-
Bacterial Proteins / genetics
-
Bacterial Proteins / metabolism*
-
Bacterial Toxins / chemistry*
-
Circular Dichroism
-
Cytotoxins / chemistry
-
Dimerization
-
Erythrocyte Membrane / metabolism
-
Erythrocyte Membrane / microbiology*
-
Erythrocytes / metabolism
-
Erythrocytes / microbiology*
-
Fluorescence Resonance Energy Transfer
-
Hemolysin Proteins / chemistry*
-
Hemolysis
-
Humans
-
Kinetics
-
Leukocidins / chemistry*
-
Leukocidins / genetics
-
Leukocidins / metabolism*
-
Membrane Glycoproteins / chemistry
-
Models, Molecular
-
Mutation
-
Perforin
-
Phosphatidylcholines / chemistry*
-
Pore Forming Cytotoxic Proteins
-
Potassium / chemistry
-
Potassium / metabolism
-
Protein Binding
-
Protein Conformation
-
Protein Structure, Secondary
-
Tryptophan / chemistry
Substances
-
Bacterial Proteins
-
Bacterial Toxins
-
Cytotoxins
-
Hemolysin Proteins
-
Hlg2 protein, Staphylococcus
-
Leukocidins
-
Membrane Glycoproteins
-
Phosphatidylcholines
-
Pore Forming Cytotoxic Proteins
-
gamma-hemolysin, Staphylococcus aureus
-
Perforin
-
LukF protein, Staphylococcus aureus
-
Tryptophan
-
Arginine
-
Potassium