Fig. 6.

RNC stability increases as the distance to the PTC increases, as determined by pulse proteolysis. (A) DHFR V75R RNC stability as a function of linker length. Blue, 35 aa from PTC; purple, 45 aa; red, 55 aa. (B) Same as A but with a stalling-deficient SecM mutant, ¹FSTPVWISQAQGIAAGA¹⁷. (C) RNase H I53D RNC stability as a function of linker length. Green, 35 aa from PTC; orange, 45 aa; yellow 55 aa. (D) Same as C except after RNase A digestion overnight. Each trace shown is representative of three separate experiments. Error bars represent the SD of the C_m determined by three separate experiments. (E) Constructs used in this study. The sequence coding for each target protein was appended with a variable size glycine-serine linker, (GS)_x, followed by the SecM stalling sequence at its C terminus. Gels of traces plotted here are present in Fig. S6.