4KR5

Crystal structure of Lactococcus lactis GlnP substrate binding domain 2 (SBD2) in open conformation

Summary for 4KR5

• Entry DOI: 10.2210/pdb4kr5/pdb
• Related: 4KPT 4KQP
• Descriptor: Glutamine ABC transporter permease and substrate binding protein protein, MAGNESIUM ION, CHLORIDE ION, ... (9 entities in total)
• Functional Keywords: glutamine/glutamic acid binding, amino acid transport, transport protein, extracellular
• Biological source: Lactococcus lactis subsp. lactis
• Total number of polymer chains: 2
• Total formula weight: 52424.70

Authors

Vujicic Zagar, A.,Guskov, A.,Schuurman-Wolters, G.K.,Slotboom, D.J.,Poolman, B. (deposition date: 2013-05-16, release date: 2013-09-11, Last modification date: 2024-02-28)

Primary citation

Fulyani, F.,Schuurman-Wolters, G.K.,Zagar, A.V.,Guskov, A.,Slotboom, D.J.,Poolman, B.
Functional Diversity of Tandem Substrate-Binding Domains in ABC Transporters from Pathogenic Bacteria.
Structure, 21:1879-1888, 2013

PubMed Abstract: The ATP-binding cassette (ABC) transporter GlnPQ is an essential uptake system for amino acids in gram-positive pathogens and related nonpathogenic bacteria. The transporter has tandem substrate-binding domains (SBDs) fused to each transmembrane domain, giving rise to four SBDs per functional transporter complex. We have determined the crystal structures and ligand-binding properties of the SBDs of GlnPQ from Enterococcus faecalis, Streptococcus pneumoniae, and Lactococcus lactis. The tandem SBDs differ in substrate specificity and affinity, allowing cells to efficiently accumulate different amino acids via a single ABC transporter. The combined structural, functional, and thermodynamic analysis revealed the roles of individual residues in determining the substrate affinity. We succeeded in converting a low-affinity SBD into a high-affinity receptor and vice versa. Our data indicate that a small number of residues that reside in the binding pocket constitute the major affinity determinants of the SBDs.

PubMed: 23994008
DOI: 10.1016/j.str.2013.07.020

Experimental method

X-RAY DIFFRACTION (1.5 Å)