Effect of topology of quorum sensing-related genes in Pectobacterium atrosepticum on their expression

In prokaryotic genomes, the neighboring genes are often located on the complementary DNA strands and adjoin each other by their 5′- or 3′-ends, or even overlap with their open reading frames. It was suggested that this gene topology has a functional purpose of regulating their expression. For the genes that overlap by their coding 3′-end encoding regions, this assumption has not been confirmed experimentally. In a broad group of bacteria that belong to proteobacteria, this convergent gene arrangement is typical for functionally connected quorum sensing-related genes “ I ” and “ R ,” which encode synthases of autoinducers, such as N -acyl homoserine lactones and their sensors, respectively. In the present study on the example of overlapping quorum sensing-related genes of plant pathogenic bacterium Pectobacterium atrosepticum SCRI1043, expI , and expR , it was shown that the topology of these genes determines the regulation of their expression.