Date Published: November 01, 2017
Publisher: International Union of Crystallography
Author(s): Christopher D. Radka, Dongquan Chen, Lawrence J. DeLucas, Stephen G. Aller.
YiuA, a Yersinia pestis substrate-binding protein, contains a putative basic triad binding motif in the canonical substrate-binding site, indicative of a metal-chelate complex binding site. Additional structural and simulation analyses support the putative function of YiuA binding bacterial siderophores.
Prokaryotic cells rely on ATP-binding cassette (ABC) transporters to facilitate substrate transport across cellular membranes. Bacterial ABC transporters are modular nanomachines that are crucial for cell viability and infection, and make up a superfamily of proteins composed of a cytoplasmic nucleotide-binding domain, a homodimer or heterodimer transmembrane permease and a substrate-binding protein (SBP) that localizes to the periplasm in Gram-negative bacteria or is anchored to the cell membrane in Gram-positive bacteria (Maqbool et al., 2015 ▸). The genes that make up bacterial ABC transporters are genetically organized into loci that are upregulated by single promoters. These single promoters are likely to be able to simultaneously upregulate multiple genes because many of the genes contain overlapping start and stop codons, which also maintain the stoichiometry of the genes by coupling translation (Price et al., 2006 ▸). In the case of iron transporters, the Fur repressor is generally considered to be the global regulator of these ABC transporter promoters (Zhou et al., 2006 ▸; Han et al., 2007 ▸; Gao et al., 2008 ▸).