Figure 2.

Fractionation of the factors involved in cma activation. Conditioned medium prepared from M9 minimal medium + glycerol was fractionated on a Sephadex G-10 column as described in the text. Column fractions 11 and 12 represented the void volume, and the M9 salts eluted at fraction 22. For fractions 12–22, the same column fraction was used to assay each of the four cma fusions by mixing 1 ml of fraction with 2 ml of 0.5× LB. The activation of each fusion was determined by β-galactosidase expression in cells at early-logarithmic phase and was normalized to the levels of expression in the absence of factor.