Figure 2.
PTS-dependent excitation response to d-glc photorelease. Excitation response of strain JWL184–1 (wild type for PTS chemotaxis) to photorelease of 4 ± 0.9 μM d-glc. The saturation response is well-fit by a single exponential (kex = 14.9 ± 0.9 s−1). Inset: Nonresponsivity of mutant strain JWL191 (ptsI) lacking EI to 15 μM d-glc photorelease. Arrows denote photolyzing flash. The prestimulus population rcd (see MATERIALS AND METHODS) means (dashed lines) ± frame-to-frame SD (dotted lines) are shown. Dashed–dotted lines indicate the rcd value for complete smooth-swimming.