Sec-independent protein translocase protein TatA/B/E (IPR003369)

Short name: TatA/B/E

Overlapping homologous superfamilies


Family relationships


Translocation of proteins across the two membranes of Gram-negative bacteria can be carried out via a number of routes. Most proteins marked for export carry a secretion signal at their N terminus, and are secreted by the general secretory pathway. The signal peptide is cleaved as they pass through the outer membrane. Other secretion systems include the type III system found in a select group of Gram-negative plant and animal pathogens, and the CagA system of Helicobacter pylori [PMID: 9649434].

In some bacterial species, however, there exists a system that operates independently of the Sec pathway [PMID: 10652088]. It selectively translocates periplasmic-bound molecules that are synthesised with, or are in close association with, "partner" proteins bearing an (S/T)RRXFLK twin arginine motif at the N terminus. The pathway is therefore termed the Twin-Arginine Translocation or TAT system. Surprisingly, the four components that make up the TAT system are structurally and mechanistically related to a pH-dependent import system in plant chloroplast thylakoid membranes [PMID: 10652088]. The gene products responsible for the Sec-independent pathway are called TatA, TatB, TatC and TatE.

This entry represents the related TatA, TatB and TatE proteins.

GO terms

Biological Process

GO:0015031 protein transport

Molecular Function

GO:0008565 protein transporter activity

Cellular Component

No terms assigned in this category.

Contributing signatures

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