SOME PROPERTIES OF DNA IN COMPETENT BACILLUS SUBTILIS

Only small fractions of populations of Bacillus subtilis, known as competent fractions, can take up transforming DNA and integrate it into their chromosomes. These competent cells have been shown in this work to possess chromosomal DNA in which about 5% of the bases are present as a single chain, whereas the remainder exist as a double chain. It has also been shown that transforming DNA is quickly converted in competent cells into a similar partially single-stranded form and it is proposed that the single-stranded regions in each associate by hydrogen bonding, thus leading to integration of transforming DNA into the chromosome and eventually, following some repair, to alteration of genetic information. © 1969.