Competence related proteins in the supernatant of competent cells of Bacillus subtilis

Summary We report that centrifugation at relatively high g-forces reduces the ability of competent cells of Bacillus subtilis to bind and take up DNA, and to be transformed. The centrifugation supernatant from competent cells restores this reduction of competence; the supernatant from non-competent cells is inactive. Phosphocellulose chromatography of centrifugation supernatants from radioactive competent cultures gave rise to six sharp peaks, together, these were shown by subsequent SDS polyacrylamide gel electrophoresis to contain over 60 different polypeptide bands. Peak II, which showed competence restoring activity, produced three polypeptides. When these bands were further examined, one of these exhibited DNA binding activity and the other two each contained a different endonuclease. Competence restoring activity was not recovered from the SDS polyacrylamide gel of peak II. The three peaks from non-competent cultures produced altogether five faint bands in gel electrophoresis. None of these bands were similar to those found in peak II.This work was performed in partial fulfillment of the requirements of Georgetown University for the degree of Doctor of Philosophy