Kinetic analysis of the products of donor deoxyribonucleate in transformed cells of Bacillus subtilis

Abstract

This paper describes the major transmutations of donor deoxyribonucleic acid (DNA) after uptake by competent Bacillus subtilis cells. Kinetic experiments confirm that after exposure to competent cells, donor DNA is converted to double-stranded fragments (DSF) which can be isolated as early as 30 s from the beginning of the reaction. At this time, DSF represent the only identifiable product of donor origin. After 1 to 2 min, DSF are converted to deoxyribonuclease-resistant forms, identified as single-stranded DNA fragments (SSF). SSF are intermediates in the transformation process leading to the formation of donor-recipient complex. This component makes its appearance between 2 to 4 min from the beginning of the transformation process. All the donor-recipient complexes found at the end of the reaction can be accounted for quantitatively by the DSF and the SSF found in the initial stages of transformation. A quantitative discussion of the transformation process is included.