简介: |
Many bacteria synthesize and secret iron-binding small molecules termed sider-ophores to obtain iron under iron-limiting conditions. Enterobactin is a prime ex-ample of a catechol-containing siderophore produced by gram-negative entericb-acteria such as Escherichia coli and Salmonella typhimurium. With a KD of 10-49M for hexadentate coordination of Fe3+, enterobactin appears admirably engine-ered for removing ferric iron from vertebrate proteins such as transferrin during infection. However, the mammalian proteins serum albumin and siderocalin bind iron-free and iron-bound enterobactin, respectively, thereby suppressing bacterialgrowth in various mammalian microenvironments. Pathogenic bacteria have evo-lved the iroA cluster (containing five genes, iroB, C, D, E, N) to counteract thehost innate immunity. In this talk, I will discuss the biochemical actions of proteins in the iroA cluster, and how they help the pathogenic bacteria to win the b-attle for iron. |
