| Primary Identifier | IPR037410 | Type | Domain |
| Short Name | BudR_PBP2 |
| description | This entry represents the substrate binding domain of BudR regulator, which is responsible for induction of the butanediol formation pathway under fermentative growth conditions. Three enzymes are involved in the production of 1 mol of 2,3 butanediol from the condensation of 2 mol of pyruvate with acetolactate and acetoin as intermediates: acetolactate synthetase, acetolactate decarboxylase, and acetoin reductase. In Klebsiella terrigena, BudR regulates the expression of the budABC operon genes, encoding these three enzymes of the butanediol pathway []. In many bacterial species, the use of this pathway can prevent intracellular acidification by diverting metabolism from acid production to the formation of neutral compounds (acetoin and butanediol). This substrate-binding domain has significant homology to the type 2 periplasmic binding proteins (PBP2).The PBP2 are responsible for the uptake of a variety of substrates such as phosphate, sulfate, polysaccharides, lysine/arginine/ornithine, and histidine. The PBP2 bind their ligand in the cleft between these domains in a manner resembling a Venus flytrap. 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 PBP2 superfamily includes the substrate- binding domains from ionotropic glutamate receptors, LysR-like transcriptional regulators, and unorthodox sensor proteins involved in signal transduction [, , ]. |
