Open AccessStructure of Stenotrophomonas maltophilia FeoA complexed with zinc: a unique prokaryotic SH3‐domain protein that possibly acts as a bacterial ferrous iron‐transport activating factor
Author(s) -
Su YiChe,
Chin KoHsin,
Hung HuiChih,
Shen GwanHan,
Wang Andrew H.J.,
Chou ShanHo
Publication year - 2010
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309110013941
Subject(s) - ferrous , stenotrophomonas maltophilia , sh3 domain , chemistry , gtpase activating protein , siderophore , protein structure , gtpase , biology , biochemistry , microbiology and biotechnology , crystallography , biophysics , receptor , bacteria , gene , genetics , g protein , proto oncogene tyrosine protein kinase src , organic chemistry , pseudomonas aeruginosa
Iron is vital to the majority of prokaryotes, with ferrous iron believed to be the preferred form for iron uptake owing to its much better solubility. The major route for bacterial ferrous iron uptake is found to be via an Feo ( fe rrous ir o n‐transport) system comprising the three proteins FeoA, FeoB and FeoC. Although the structure and function of FeoB have received much attention recently, the roles played by FeoA and FeoC have been little investigated to date. Here, the tertiary structure of FeoA from Stenotrophomonas maltophilia ( Sm ), a vital opportunistic pathogen in immunodepressed hosts, is reported. The crystal structure of Sm FeoA has been determined to a resolution of 1.7 Å using an Se single‐wavelength anomalous dispersion (Se‐SAD) approach. Although Sm FeoA bears low sequence identity to eukaryotic proteins, its structure is found to adopt a eukaryotic SH3‐domain‐like fold. It also bears weak similarity to the C‐terminal SH3 domain of bacterial DtxR (diphtheria toxin regulator), with some unique characteristics. Intriguingly, Sm FeoA is found to adopt a unique dimer cross‐linked by two zinc ions and six anions (chloride ions). Since FeoB has been found to contain a G‐protein‐like domain with low GTPase activity, FeoA may interact with FeoB through the SH3–G‐protein domain interaction to act as a ferrous iron‐transport activating factor.