Force Transduction and Lipid Binding in MscL: A Continuum-Molecular Approach
(A) Cartoon representation of MscL highlighting all the Phe (green) and cytoplasmic Lys (magenta) amino acids in two of the protein monomers, highlighted in light yellow and blue. For clarity, one monomer (blue) shows only the lysines on the S1 domain (K3 and K6), and the adjacent monomer (yellow) shows only the lysines on TM2 (K99 and K100). Lipids that hydrogen-bond the selected lysines are shown in gray. (B) Common hydrogen-bonding pattern observed between the oxygens in the negatively-charged portion of the lipid headgroup and the positively-charged Lys. (C) Lipid tails of tightly-bound lipids accommodate in cavities as shown in a vertical cross section of a surface representation of MscL.