FIG 7.

Restoration of compromised ArgO function by compensatory amino acid substitutions. (A) Samples of 5 μl of 10,000-fold-diluted stationary-phase cultures of GJ4823 bearing the vector or plasmid pHYD2835 encoding C-terminally HA-tagged ArgO and its plasmid derivatives encoding ArgO bearing the single and double amino acid substitutions indicated were spotted onto the surface of an MA agar plate (I, III, V, and VII) and an MA agar plate containing 2 μg/ml Can (II, IV, VI, and VIII). (B) Levels of the single- and double-substitution-bearing ArgO proteins indicated were detected by immunoblotting with anti-HA antibody. Sample loading was done as described in the legend to Fig. 5, and the ArgO-encoding plasmids indicated are described in Table S1 in the supplemental material.