Isochorismate synthase 1; Involved in the biosynthesis of the siderophore enterobactin (macrocyclic trimeric lactone of N-(2,3-dihydroxybenzoyl)-serine). Catalyzes the reversible conversion of chorismate to isochorismate.

Ferrienterobactin outer membrane transporter; This protein is involved in the initial step of iron uptake by binding ferrienterobactin (Fe-ENT), an iron chelatin siderophore that allows E.coli to extract iron from the environment. FepA also acts as a receptor for colicins B and D.

Membrane spanning protein in TonB-ExbB-ExbD complex; Involved in the TonB-dependent energy-dependent transport of various receptor-bound substrates. Protects ExbD from proteolytic degradation and functionally stabilizes TonB.

Isochorismatase; Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3- dihydroxybenzoyl)-serine. The serine trilactone serves as a scaffolding for the three catechol functionalities that provide hexadentate coordination for the tightly ligated iron(2+) atoms. EntB is a bifunctional protein that serves as an isochorismate lyase and an aryl carrier protein (ArCP). Catalyzes the conversion of isochorismate to 2,3-dihydro-2,3-dihydroxybenzoate (2,3-diDHB), the precursor of 2,3- dihydroxybenzoate (DHB). In the enterob [...]

Enterobactin/ferrienterobactin esterase; Upon internalization, ferric enterobactin is processed via an exquisitely specific pathway that is dependent on FES activity, making iron available for metabolic use; Belongs to the Fes family.

Membrane spanning protein in TonB-ExbB-ExbD transport complex; Interacts with outer membrane receptor proteins that carry out high-affinity binding and energy dependent uptake into the periplasmic space of specific substrates such as cobalamin, and various iron compounds (such as iron dicitrate, enterochelin, aerobactin, etc.). In the absence of TonB these receptors bind their substrates but do not carry out active transport. TonB also interacts with some colicins and is involved in the energy-dependent, irreversible steps of bacteriophages phi 80 and T1 infection. It could act to tran [...]

Membrane spanning protein in TonB-ExbB-ExbD complex; Involved in the TonB-dependent energy-dependent transport of various receptor-bound substrates.

Ferrienterobactin ABC transporter ATPase; Part of the binding-protein-dependent transport system for ferric enterobactin. Probably responsible for energy coupling to the transport system.

Catecholate siderophore receptor; Involved in the active transport across the outer membrane of iron complexed with catecholate siderophores such as dihydroxybenzoylserine and dihydroxybenzoate. It derives its energy for transport by interacting with the trans-periplasmic membrane protein TonB. Can also transport catechol-substituted cephalosporins. Receptor for microcins M, H47 and E492.