Figure 6.

AI-2 import in V. harveyi. (A) Whether V. harveyi is able to internalize AI-2 molecules or not (circled arrow marked with question mark) can be predicted from its encoder profile. A low-pass profile implies the capacity for import, an ideal profile suggests that such a capacity is lacking. (B) The form of the AI-2 encoder sensitivity profile for V. harveyi derived from data in a previous study (26) is qualitatively compatible with the behavior of a low-pass encoder. This implies the presence of an uptake mechanism for AI-2 molecules in V. harveyi. (C) Schematic representation of the heterologous lsrKR-based P_lsr::lacZ reporter system in V. harveyi. (D) Histograms showing β−galactosidase activity (as a measure of P_lsr::lacZ expression) of AI-2-producing V. harveyi wild-type cells, the nonproducing mutant (ΔluxS) and the nonproducing mutant after external addition of AI-2 (20 μM).