I-V relationships for the two dominant channel conductances in V. cholerae. (A and B) Examples of single-channel currents at opposite voltages for both the MscL-like and MscS-like channels. Note fast-flickering subconductance levels in MscS at negative pipette potentials. (C) I-V plot of MscL-like (squares) and MscS-like channels (circles). Filled squares represent the Rs-corrected curve for MscL. MscS shows obvious inward rectification.