biostudies-literatureKumar ABLRD VAThe Department of Veterans Affairs VA Merit ReviewNIAID NIH HHSNIHNIH HHSe0002424https://www.ebi.ac.uk/biostudies/studies/S-EPMC11112993biostudies-literatureUnknown206(5)Microbes synthesize and secrete siderophores, that bind and solubilize precipitated or otherwise unavailable iron in their microenvironments. Gram (-) bacterial TonB-dependent outer membrane receptors capture the resulting ferric siderophores to begin the uptake process. From their similarity to <i>fepA,</i> the structural gene for the <i>Escherichia coli</i> ferric enterobactin (FeEnt) receptor, we identified four homologous genes in the human and animal ESKAPE pathogen <i>Klebsiella pneumoniae</i> (strain Kp52.145). One locus encodes IroN (locus <i>0027</i> on plasmid pII), and three other loci encode other FepA orthologs/paralogs (chromosomal loci <i>1658, 2380,</i> and <i>4984</i>). Based on the crystal structure of <i>E. coli</i> FepA (1FEP), we modeled the tertiary structures of the Journal of bacteriologySiderophore-mediated iron acquisition by <i>Klebsiella pneumoniae</i>.PMC11112993I01 BX004677R21 AI141826R21 AI088318R21 AI123558I01 BX004677-01R21 AI123558-01 and 1R21AI141826-01A1Newton SMChakravorty SKlebba PEYang TKumar ARusso TAfalseSiderophore-mediated iron acquisition by <i>Klebsiella pneumoniae</i>.Microbes synthesize and secrete siderophores, that bind and solubilize precipitated or otherwise unavailable iron in their microenvironments. Gram (-) bacterial TonB-dependent outer membrane receptors capture the resulting ferric siderophores to begin the uptake process. From their similarity to <i>fepA,</i> the structural gene for the <i>Escherichia coli</i> ferric enterobactin (FeEnt) receptor, we identified four homologous genes in the human and animal ESKAPE pathogen <i>Klebsiella pneumoniae</i> (strain Kp52.145). One locus encodes IroN (locus <i>0027</i> on plasmid pII), and three other loci encode other FepA orthologs/paralogs (chromosomal loci <i>1658, 2380,</i> and <i>4984</i>). Based on the crystal structure of <i>E. coli</i> FepA (1FEP), we modeled the tertiary structures of the 2024-01-01T00:00:00Z2024 May2026-06-13T05:39:49.323Z2025-04-06T12:30:29.059ZS-EPMC111129933859191310.1128/jb.00024-24