Substrate binding domain of putative TAXI proteins of the tripartite ATP-independent periplasmic transporters; the type 2 periplasmic binding protein fold.
This subgroup includes uncharacterized periplasmic binding proteins that are related to Thermus thermophilus GluBP (TtGluBP) of TAXI-TRAP family. TRAP transporters are comprised of an SBP (substrate-binding protein) and two unequally sized integral membrane components. Although TtGluBP is predicted to be an L-glutamate and/or an L-glutamine-binding protein, the substrate spectrum of TAXI proteins remains to be defined. A sequence-homology search also shows that TtGluBP shares low sequence homology with putative immunogenic proteins of uncharacterized function.
Jiyao W et al.(2023). "The conserved domain database in 2023.",