Polysialic and colanic acids metabolism in Escherichia coli K92 is regulated by RcsA and RcsB

摘要: We have shown previously that Escherichia coli K92 produces two different capsular polymers known as CA (colanic acid) and PA (polysialic in a thermoregulated manner. The complex Rcs phosphorelay is largely related to the regulation of synthesis. Through deletion rscA rscB genes, we show system involved both synthesis E. K92. Deletion either rcsA or rcsB genes resulted decreased expression cps (CA biosynthesis cluster) at 19°C 37°C, but only production was reduced 19°C. Concerning PA, deletions enhanced its which does not correlate with kps (PA observed mutant. Under this condition, nan operon responsible for catabolism greatly reduced. Although RcsA RcsB acted negative regulators their absence did reestablish low temperatures, despite resulting expression. Finally, our results revealed controlled several (dsrA, rfaH, h-ns slyA) thermoregulation synthesis, indicating part regulatory mechanism governing surface appearance coli.