Amino acid-binding domain of the type 2 periplasmic binding fold superfamily.
This subfamily includes the periplasmic binding protein type II (BPBII). This domain is found in solute binding proteins that serve as initial receptors in the ABC transport, signal transduction and channel gating. The PBPII proteins share the same architecture as periplasmic binding proteins type I (PBPI), but have a different topology. They are typically comprised of two globular subdomains connected by a flexible hinge and bind their ligand in the cleft between these domains in a manner resembling a Venus flytrap. The majority of PBPII proteins function in the uptake of small soluble substrates in eubacteria and archaea. After binding their specific ligand with high affinity, they can interact with a cognate membrane transport complex comprised of two integral membrane domains and two cytoplasmically-located ATPase domains. This interaction triggers the ligand translocation across the cytoplasmic membrane energized by ATP hydrolysis. Besides transport proteins, the family includes ionotropic glutamate receptors and unorthodox sensor proteins involved in signal transduction.
Feature 1:ligand binding site [chemical binding site]
Evidence:
Structure:3K4U; putative binding component Of Abc transporter from Wolinella succinogenes Dsm 1740 in complex with Lysine, contacts at 4A. - View structure with Cn3D
Jiyao W et al.(2023). "The conserved domain database in 2023.",