4KPT: Crystal Structure of Substrate Binding Domain 1 (Sbd1) of ABC Transporter Glnpq From Lactococcus Lactis

Citation:
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.
PDB ID: 4KPTDownload
MMDB ID: 113422
PDB Deposition Date: 2013/5/14
Updated in MMDB: 2013/11
Experimental Method:
x-ray diffraction
Resolution: 1.4  Å
Source Organism:
Similar Structures:
Biological Unit for 4KPT: monomeric; determined by author and by software (PISA)
Molecular Components in 4KPT
Label Count Molecule
Protein (1 molecule)
1
Glutamine ABC Transporter Permease and Substrate Binding Protein Protein
Molecule annotation
Chemicals (13 molecules)
1
1
2
2
3
2
4
1
5
7
* Click molecule labels to explore molecular sequence information.

Citing MMDB
.