6B2X

Apo YiuA Crystal Form 1

Summary for 6B2X

• Entry DOI: 10.2210/pdb6b2x/pdb
• Descriptor: Solute-binding periplasmic protein of iron/siderophore ABC transporter, CHLORIDE ION, SODIUM ION, ... (4 entities in total)
• Functional Keywords: transition metal homeostasis, yersinia pestis, cluster a-2, substrate-binding protein, metal transport
• Biological source: Yersinia pestis
• Total number of polymer chains: 2
• Total formula weight: 87490.34

Authors

Radka, C.D.,DeLucas, L.J.,Aller, S.G. (deposition date: 2017-09-20, release date: 2017-11-15, Last modification date: 2024-10-09)

Primary citation

Radka, C.D.,Chen, D.,DeLucas, L.J.,Aller, S.G.
The crystal structure of the Yersinia pestis iron chaperone YiuA reveals a basic triad binding motif for the chelated metal.
Acta Crystallogr D Struct Biol, 73:921-939, 2017

PubMed Abstract: Biological chelating molecules called siderophores are used to sequester iron and maintain its ferric state. Bacterial substrate-binding proteins (SBPs) bind iron-siderophore complexes and deliver these complexes to ATP-binding cassette (ABC) transporters for import into the cytoplasm, where the iron can be transferred from the siderophore to catalytic enzymes. In Yersinia pestis, the causative agent of plague, the Yersinia iron-uptake (Yiu) ABC transporter has been shown to improve iron acquisition under iron-chelated conditions. The Yiu transporter has been proposed to be an iron-siderophore transporter; however, the precise siderophore substrate is unknown. Therefore, the precise role of the Yiu transporter in Y. pestis survival remains uncharacterized. To better understand the function of the Yiu transporter, the crystal structure of YiuA (YPO1310/y2875), an SBP which functions to present the iron-siderophore substrate to the transporter for import into the cytoplasm, was determined. The 2.20 and 1.77 Å resolution X-ray crystal structures reveal a basic triad binding motif at the YiuA canonical substrate-binding site, indicative of a metal-chelate binding site. Structural alignment and computational docking studies support the function of YiuA in binding chelated metal. Additionally, YiuA contains two mobile helices, helix 5 and helix 10, that undergo 2-3 Å shifts across crystal forms and demonstrate structural breathing of the c-clamp architecture. The flexibility in both c-clamp lobes suggest that YiuA substrate transfer resembles the Venus flytrap mechanism that has been proposed for other SBPs.

PubMed: 29095164
DOI: 10.1107/S2059798317015236

Experimental method

X-RAY DIFFRACTION (2.199 Å)