7LB8
Structure of a ferrichrome importer FhuCDB from E. coli
Summary for 7LB8
| Entry DOI | 10.2210/pdb7lb8/pdb |
| EMDB information | 23251 |
| Descriptor | Iron(3+)-hydroxamate import system permease protein FhuB, Iron(3+)-hydroxamate-binding protein FhuD, Iron(3+)-hydroxamate import ATP-binding protein FhuC (3 entities in total) |
| Functional Keywords | abc importer, siderophore, cryo-em, transport protein |
| Biological source | Escherichia coli (strain K12) More |
| Total number of polymer chains | 4 |
| Total formula weight | 162447.97 |
| Authors | |
| Primary citation | Hu, W.,Zheng, H. Cryo-EM reveals unique structural features of the FhuCDB Escherichia coli ferrichrome importer. Commun Biol, 4:1383-1383, 2021 Cited by PubMed Abstract: As one of the most elegant biological processes developed in bacteria, the siderophore-mediated iron uptake demands the action of specific ATP-binding cassette (ABC) importers. Although extensive studies have been done on various ABC importers, the molecular basis of these iron-chelated-siderophore importers are still not fully understood. Here, we report the structure of a ferrichrome importer FhuCDB from Escherichia coli at 3.4 Å resolution determined by cryo electron microscopy. The structure revealed a monomeric membrane subunit of FhuB with a substrate translocation pathway in the middle. In the pathway, there were unique arrangements of residues, especially layers of methionines. Important residues found in the structure were interrogated by mutagenesis and functional studies. Surprisingly, the importer's ATPase activity was decreased upon FhuD binding, which deviated from the current understanding about bacterial ABC importers. In summary, to the best of our knowledge, these studies not only reveal a new structural twist in the type II ABC importer subfamily, but also provide biological insights in the transport of iron-chelated siderophores. PubMed: 34887516DOI: 10.1038/s42003-021-02916-2 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.4 Å) |
Structure validation
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