Figure 13.

Gating characteristics of the different T-domain constructs studied on a single-channel level ³²⁸. A: A single channel formed by wild-type T-domain (lacking H6 tag) remains open at both +60 and −60 mV, with irresolvably brief flickerings to a zero-conductance closed state. B: A single channel formed by T-domain with an N-terminal H6 tag remains open at +65 mV but rapidly closes to zero conductance at −65 mV. C: A single channel formed by T-domain with a C-terminal H6 tag spends a good deal of time in the zero-conductance closed state at +65 mV and remains open at −65 mV like the wild-type channel. D: A single channel formed by T-domain with both N- and C-terminal H6 tags is blocked at both +65 and −65 mV. At positive voltages, the channel fluctuates rapidly between the open and closed states, spending about half of its time in each. At negative voltage pulses, the channel remains open briefly, before fully closing for the duration of the pulse. Reprinted with permission from ref³²⁸. Copyright 2001. The Rockefeller University Press.