Essential Residues, W177 and R198, of LukF for Phosphatidylcholine-Binding and Pore-Formation by Staphylococcal [gamma]-Hemolysin on Human Erythrocyte Membranes

• Published in: Journal of biochemistry (Tokyo) Vol. 136; no. 4; pp. 427 - 431
• Main Authors: Monma, Naota, Nguyen, Vananh T, Kaneko, Jun, Higuchi, Hideo, Kamio, Yoshiyuki
• Format: Journal Article
• Language: English
• Published: 01-10-2004
• ISSN: 0021-924X; 1756-2651
• DOI: 10.1093/jb/mvh140

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.