periplasmic L-arabinose-binding protein (ABP), a member of a family of pentose/hexose sugar-binding proteins of the type 1 periplasmic binding protein superfamily
Periplasmic L-arabinose-binding protein (ABP), a member of a family of pentose/hexose sugar-binding proteins of the type 1 periplasmic binding protein superfamily. ABP is only involved in transport contrary to other related sugar-binding proteins such as the glucose/galactose-binding protein (GGBP) and the ribose-binding protein (RBP), both of which are involved in chemotaxis as well as transport. The periplasmic ABP consists of two alpha/beta globular domains connected by a three-stranded hinge, a Venus flytrap-like domain, which undergoes a transition from an open to a closed conformational state upon ligand binding. Moreover, ABP is homologous to the ligand-binding domain of eukaryotic receptors such as metabotropic glutamate receptor (mGluR) and DNA-binding transcriptional repressors such as LacI and GalR.