Ectoine/Hydroxyectoine ABC transporter, substrate-binding protein EhuB (IPR014337)

Short name: Ectoine_EhuB

Overlapping homologous superfamilies


Family relationships



This family represents the periplasmic substrate-binding proteins (PBPs) of ABC transport systems that are involved in the uptake of osmoprotectants (also termed compatible solutes) such as ectoine and hydroxyectoine. To counteract the efflux of water, bacteria and archaea accumulate the compatible solutes for a sustained adjustment to high osmolarity surroundings [PMID: 17996893]. This family are an example of type 2 periplasmic binding fold proteins, which are typically 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 [PMID: 11741199].

This entry is named for one of the constituent proteins from Rhizobium meliloti (Sinorhizobium meliloti), involved in ectoine and 5-hydroxyectoine uptake, both for osmoprotection and for catabolism. The crystal structure of EhuB was solved in complex with either ectoine or 5-hydroxyectoine [PMID: 17996893].

GO terms

Biological Process

GO:0051470 ectoine transport

Molecular Function

GO:0033294 ectoine binding

Cellular Component

No terms assigned in this category.

Contributing signatures

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