Competent Bacillus subtilis cultures synthesize a denatured DNA binding activity.

A protein activity has been detected in soluble extracts of competent cultures of bacillus subtilis which protects denatured DNA from nuclease solubilization. Both binding activity and competence development occur simultaneously but not coordinately, since the peak of binding activity appears 3 hr after the peak of competence. The binding activivity is not detected in physiologically noncompetent cultures, in an isogenic noncompetent cultures, in an isogenic noncompetent mutant grown through the competence regimen, or in early sporulating cells. The activity is included on Sephadex G-100 gel filtration columns but elutes in a broad nonhomogeneous peak. This binding activity may play a role in uptake of DNA and/or integration of exogenous DNA into the genome of competent B. subtilis cells.