Fig. 3.

Effect of changes in osmolarity of the culture medium on Xer site-specific recombination at mwr. Schematic representation of the possible chain of events that lead to a higher efficiency of Xer site-specific recombination at the K. pneumoniae plasmid pJHCMW1 site mwr. A decrease in the NaCl concentration in the growth medium (L broth containing 0.5% NaCl added to no NaCl added) is correlated with an increase in supercoiling density, which facilitates interaction of ArgR with the substandard mwr ARG box leading to a more efficient formation of a productive synaptic complex and Holliday junction (78). Molecular models of the interwrapped synaptic complex are available at the following references (146-148). The two strands are shown only in the core recombination site (red and green lines), blue lines represent the accessory sequences.