Bacterial periplasmic spermidine/putrescine-binding protein (IPR001188)

Short name: Sperm_putr-bd

Overlapping homologous superfamilies


Family relationships



Bacterial high affinity transport systems are involved in active transport of solutes across the cytoplasmic membrane. The protein components of these traffic systems include one or two transmembrane protein components, one or two membrane-associated ATP-binding proteins and a high affinity periplasmic solute-binding protein. In Gram-positive bacteria, which are surrounded by a single membrane and therefore have no periplasmic region, the equivalent proteins are bound to the membrane via an N-terminal lipid anchor. These homologue proteins do not play an integral role in the transport process per se, but probably serve as receptors to trigger or initiate translocation of the solute through the membrane by binding to external sites of the integral membrane proteins of the efflux system. In addition at least some solute-binding proteins function in the initiation of sensory transduction pathways.

The bacterial periplasmic spermidine/putrescine-binding proteins are involved in the polyamine transport system. They are required for the activity of the bacterial periplasmic transport system of putrescine and spermidine [PMID: 1939142, PMID: 8416922].

GO terms

Biological Process

GO:0015846 polyamine transport

Molecular Function

GO:0019808 polyamine binding

Cellular Component

GO:0042597 periplasmic space

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.