The Ferric Hydroxamate Uptake ReceptorFhuAand RelatedTonB‐Dependent Transporters in the Outer Membrane of Gram‐Negative Bacteria

Abstract

FUNCTIONAL CLASS chemiosmotic gradient; ABC transporter; bacteriophage infection; colicin import; siderophore-antibiotic conjugate and peptide antibiotic sensitivity; Ton B-dependent receptor; structurally related to the ferric enterobactin receptor, and Active transporter; siderophore; integral outer membrane protein; ferric hydroxamate uptake receptor, known as FhuA; (a) (b) 3D Structure The three-dimensional structure of FhuA in complex with ferricrocin. (a) FhuA in ribbon representation. The view is perpendicular to the barrel axis. The strands that comprise the front of th e barrel domain have bee n removed to provide an un obstructed view of the cork domain. (b) FlllI A as viewed from th e externa l environment along the barrel axis. In panels a and b, the bar rel domalll (residues 161-714) and the cork domain (residues 1-160) are colored blue and ye ll ow, respectively. The ferr icrocin molecule IS shown as a bond model with carbon atoms white, oxygen atoms red, and nitrogen atoms blue. The ::rric iron atom is shown as a large red sphere. These and all the following color fi gures were prepared using MOLSCl111'T 95 ancl I1AST EII3 D. PDB code: IQFF. 834 FClnclu'O llle T I. 1'5.<1'80. UC-I Col /vl M 1C1OC li t J25 Dbs !\ lboIllYCIll Rhodotul1I lil le Elll erob.1clill Dill> Dbh CGP ,ISJ, Aeroonelill ('o!>l oge n Col B.D Col ln.lb.V ('01 G,II