Selective release of a deoxyribonucleic acid-binding factor from the surface of competent pneumococci

Methods are described that resulted in the selective release of deoxyribonucleic acid (DNA)-binding factor from the surface of competent pneumococci. The same methods caused a parallel inactivation of the DNA-binding capacity of the extracted bacteria. Genetically or physiologically incompetent pneumococci did not yield binding factor upon exposure to the same methods. The solubilized binding factor appeared to be a protein; it could be assayed by a membrane filter binding procedure. The binding factor had properties reminiscent of those of the DNA receptors of transformable pneumococci (Seto et al., 1975).