2GZR

Enterobactin and Salmochelin Hydrolase IroE

Summary for 2GZR

• Entry DOI: 10.2210/pdb2gzr/pdb
• Related: 2GZS
• Descriptor: IroE protein (1 entity in total)
• Functional Keywords: serine hydrolase, catalytic dyad, enterobactin, hydrolase
• Biological source: Escherichia coli
• Total number of polymer chains: 1
• Total formula weight: 31014.00

Authors

Larsen, N.A.,Walsh, C.T. (deposition date: 2006-05-11, release date: 2006-09-05, Last modification date: 2024-11-13)

Primary citation

Larsen, N.A.,Lin, H.,Wei, R.,Fischbach, M.A.,Walsh, C.T.
Structural Characterization of Enterobactin Hydrolase IroE.
Biochemistry, 45:10184-10190, 2006

PubMed Abstract: The proliferation of many pathogenic bacteria is limited by the scarcity of soluble iron in their environment. Many of these bacteria scavenge iron by synthesizing and exporting small molecule siderophores that chelate iron. Iron-bound siderophores are subsequently imported for metabolic processing. Three related serine hydrolases have been characterized biochemically in this pathway: Fes, IroD, and IroE. Here, we report the crystal structure of IroE from uropathogenic Escherichia coli CFT073. The native structure and a complex with diisopropyl fluorophosphonate (DFP, a potent serine hydrolase inhibitor) were determined at 2.3 and 1.4 A resolution, respectively. IroE has the typical alpha/beta-hydrolase fold with an atypical catalytic dyad composed of Ser 189 and His 287. Mutation of either residue was detrimental to catalysis. In addition, rather than the typical oxyanion hole composed of backbone amides, IroE employs the atypical guanidinium moiety of Arg 130. Asp 90 anchors Arg 130 in the active site, and mutation of either residue was likewise detrimental to catalysis. We also compare the structure of IroE to the structure of Fes from Shigella flexneri (PDB entry 2B20). Both enzymes have similar active sites, but Fes has an additional amino-terminal lid domain. These lid domains are proposed to confer specificity to these related hydrolases.

PubMed: 16922493
DOI: 10.1021/bi060950i

Experimental method

X-RAY DIFFRACTION (2.3 Å)