The initial attachment of transforming DNA to competent Bacillus subtilis.

The initial attachment of transforming DNA to competent Bacillus subtilis is temperature independent between 25 degrees and 45 degrees. However, below 15 degrees there is a significant reduction in the amount of DNA attached to compentent cells. The DNA that is attached at 4 degrees can lead to transformation or interfere effectively with the subsequent attachment of a distinctive DNA when the cells are shifted to a permissive temperature (37 degrees). These data suggest that the attachment of DNA at 4 degrees is to sites normally involved in the transformation process. The amount of DNA that is initially attached to the bacteria at 4 degrees or 37 degrees after perturbation of the cells by ionic strength changes, repetitive washings, or periodate oxidation varies with the temperature at which the treatment occurs. These results are consistent with a reorientation of the DNA attachment sites upon lowering the temperature to 4 degrees, such that their affinity for DNA and susceptibility inhibitory treatments are reduced.