Evidence that RpoS (σ S ) in Borrelia burgdorferi Is Controlled Directly by RpoN (σ ⁵⁴ /σ N )

The alternative sigma factor (RpoN-RpoS) pathway controls the expression of key virulence factors in Borrelia burgdorferi. However, evidence to support whether RpoN controls rpoS directly or, perhaps, indirectly via a transactivator has been lacking. Herein we provide biochemical and genetic evidence that RpoN directly controls rpoS in B. burgdorferi.