8GMM

Stenotrophomonas maltophilia Holo HphA

Summary for 8GMM

• Entry DOI: 10.2210/pdb8gmm/pdb
• Descriptor: Hemophilin, HEME B/C (3 entities in total)
• Functional Keywords: heme binding, hemophore, type xi secretion system cargo, beta barrel, metal transport
• Biological source: Stenotrophomonas maltophilia
• Total number of polymer chains: 2
• Total formula weight: 51593.92

Authors

Shin, H.E.,Moraes, T.F. (deposition date: 2023-03-26, release date: 2024-03-27, Last modification date: 2024-07-03)

Primary citation

Shin, H.E.,Pan, C.,Curran, D.M.,Bateman, T.J.,Chong, D.H.Y.,Ng, D.,Shah, M.,Moraes, T.F.
Prevalence of Slam-dependent hemophilins in Gram-negative bacteria.
J.Bacteriol., 206:e0002724-e0002724, 2024

PubMed Abstract: Iron acquisition systems are crucial for pathogen growth and survival in iron-limiting host environments. To overcome nutritional immunity, bacterial pathogens evolved to use diverse mechanisms to acquire iron. Here, we examine a heme acquisition system that utilizes hemophores called hemophilins which are also referred to as HphAs in several Gram-negative bacteria. In this study, we report three new HphA structures from , , and . Structural determination of HphAs revealed an N-terminal clamp-like domain that binds heme and a C-terminal eight-stranded β-barrel domain that shares the same architecture as the Slam-dependent Neisserial surface lipoproteins. The genetic organization of HphAs consists of genes encoding a Slam homolog and a TonB-dependent receptor (TBDR). We investigated the Slam-HphA system in the native organism or the reconstituted system in cells and found that the efficient secretion of HphA depends on Slam. The TBDR also played an important role in heme uptake and conferred specificity for its cognate HphA. Furthermore, bioinformatic analysis of HphA homologs revealed that HphAs are conserved in the alpha, beta, and gammaproteobacteria. Together, these results show that the Slam-dependent HphA-type hemophores are prevalent in Gram-negative bacteria and further expand the role of Slams in transporting soluble proteins.

PubMed: 38814789
DOI: 10.1128/jb.00027-24

Experimental method

X-RAY DIFFRACTION (1.8 Å)