Fig 1.

Chemotactic responses of the classical V. cholerae strain to amino acids. (A) Capillary assay of responses of strain O395N1 to serine (attractant) and glutamate (nonattractant). Closed circles, O395N1 (Che⁺); open circles, VcheA2 (ΔcheA2). (B) Summary of the results of competition assays. Preincubation with proline failed to inhibit serine taxis, while that with serine inhibited proline taxis. (C) Competition between different attractants in chemotaxis of V. cholerae. O395N1 (closed circles) and VcheA2 (open circles) were preincubated with TMN buffer (+ None), 10 mM cysteine, and 10 mM proline and were examined for responses to serine.