Figure 4. Apparent chemoattractant response of Rluc PCA reflects nonspecific inhibition of full-length Rluc.

Luminescence generated by wild-type V. cholerae co-expressing CheY3-RlucN and CheZ-RlucC from pYNZC (A) or unfused, full-length Rluc from pRluc (B) was measured before and after treatment with 1 mM D-glucose, L-alanine, or nickel chloride (top panel) and 1 mM L-serine, D-mannose, or L-arginine (bottom panel) or an equal volume of water. Luminescence generated by wild-type E. coli expressing full-length Rluc from pRluc was measured before and after treatment with L-serine, L-arginine, or water (C). Reagent addition is denoted by an arrow. Data are reported as a percentage of the highest initial signal intensity and represent the average of three technical replicates.