9GAR

Siderophore-binding lipoprotein XusB from Barnesiella viscericola

Summary for 9GAR

• Entry DOI: 10.2210/pdb9gar/pdb
• Descriptor: DUF4374 domain-containing protein, SULFATE ION, ACETATE ION (3 entities in total)
• Functional Keywords: outer membrane, lipoprotein, siderophore, iron piracy, metal transport
• Biological source: Barnesiella viscericola DSM 18177
• Total number of polymer chains: 1
• Total formula weight: 52440.27

Authors

Silale, A.,Soo, Y.L.,van den Berg, B. (deposition date: 2024-07-29, release date: 2025-08-06, Last modification date: 2025-09-17)

Primary citation

Silale, A.,Soo, Y.L.,Mark, H.,Motz, R.N.,Basle, A.,Nolan, E.M.,van den Berg, B.
Structural basis of iron piracy by human gut Bacteroides.
Biorxiv, 2025

PubMed Abstract: Iron is an essential element that can be growth-limiting in microbial communities, particularly those present within host organisms. To acquire iron, many bacteria secrete siderophores, secondary metabolites that chelate ferric iron. These iron chelates can be transported back into the cell via TonB-dependent transporters in the outer membrane, followed by intracellular liberation of the iron. Pathogenic and produce siderophores during gut infection. In response to iron starvation, the human gut symbiont upregulates an iron piracy system, XusABC, which steals iron-bound siderophores from the invading pathogens. Here, we investigated the molecular details of xenosiderophore uptake across the outer membrane by the XusAB complex. Our crystal and cryogenic electron microscopy structures explain how the XusB lipoprotein recognises iron-bound xenosiderophores and passes them on to the XusA TonB-dependent transporter. Moreover, we show that Xus homologues can transport a variety of siderophores with different iron-chelating functional groups.

PubMed: 40894706
DOI: 10.1101/2024.04.15.589501

Experimental method

X-RAY DIFFRACTION (3.2 Å)