Fig. 5.

Examples of Tsr control cable mutants with ATT-mimic [2] signaling defects. (A) Output curves for Tsr(I214D) and Tsr(I214R). See Fig. 4A for further explanation. (B) Modification profiles of the I214D and I214R mutant receptors in various hosts. The band marked with a black triangle corresponds to the faster of the two heavily methylated bands produced by wild-type Tsr in the same host strain. Unlabeled lanes are EEEE/QEQE/QQQQ markers (Fig. 3B). (C) Modification profiles of the I214D and I214R mutant receptors in an adaptation-competent (CheR⁺ CheB⁺) host before (−) and after (+) experiencing a serine stimulus. The white triangle indicates a chromosomally encoded nonreceptor protein that cross-reacts with the anti-Tsr antibody. The black triangle marks the same band as that described above in panel B. Unlabeled lanes are EEEE/QEQE/QQQQ markers (Fig. 3B).