The periplasmic substrate-binding component of an ABC-type polyamine transport system from Treponema pallidum and related proteins; contains the type 2 periplasmic binding fold.
This group includes the polyamine-binding component of an ABC-type polyamine transport system from Treponema pallidum and closely related proteins, which is homologous to the spermidine-preferring periplasmic substrate-binding protein component (PotD)of ABC transport system. Polyamine transport plays an essential role in the regulation of intracellular polyamine levels which are known to be elevated in rapidly proliferating cells and tumors. Natural polyamines are putrescine, spermindine, and spermine. They are polycations that play multiple roles in cell growth, survival and proliferation, as well as plant stress and disease resistance. They can interact with negatively charged molecules, such as nucleic acids, to modulate their functions. Members of this family belong to the type 2 periplasmic-binding fold superfamily. PBP2 is 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.
Feature 1:chemical substrate binding site [chemical binding site]
Evidence:
Structure:2V84; the Tp0655 (Tppotd) lipoprotein Of Treponema pallidum binds 2-(N-morpholino)ethanesulfonic acid (MES), a buffer component included in the crystallization medium; contacts at 4A.
Comment:one of the MES-binding sites in Tp0655 coincides with the polyamine-binding sites in PotD and PotF.
Jiyao W et al.(2023). "The conserved domain database in 2023.",