FREQUENCY OF DELETION FORMATION DECREASES EXPONENTIALLY WITH DISTANCEBETWEEN SHORT DIRECT REPEATS

The effect of distance between 18 bp direct repeats on deletion format ion has been examined in Bacillus subtilis. The deletion frequency dec reased exponentially by more than 1000-fold as the distance increased from 33 to 2313 bp. This decrease occurred in two distinct phases, whi ch may be determined by DNA-duplex flexibility A similar relationship between deletion formation and distance was observed in a theta-replic ating plasmid and in the chromosome, indicating that this relationship might have a general validity.