Pathogenic Microbiology Commons^™

The Regulation Of The Icsp Promoter Of Shigella Flexneri By Ryhb, Lia A. Africa, Helen J. Wing

Undergraduate Research Opportunities Program (UROP)

Iron is an essential element in the metabolism of many organisms, including bacteria. In many pathogenic bacteria, the levels of iron present trigger the expression of many virulence genes. In Shigella, a gram-negative bacterium that causes dysentery in humans, the expression of a small regulatory RNA, ryhB, is blocked in the presence of iron. Studies have revealed that ryhB represses virB, a global regulator of virulence genes in Shigella.

The icsP gene is under the direct control of VirB. icsP encodes an outer membrane protease that cleaves a protein necessary for the actin tail assembly of Shigella in vitro. In …