Bacterial export protein family 3 (IPR002191)

Short name: Bac_export_3

Overlapping homologous superfamilies


Family relationships


The fliL operon of Escherichia coli contains seven genes (including fliO, fliP, fliQ and fliR) involved in the biosynthesis and functioning of the flagellar organelle [PMID: 8282695]. The fliO, fliP, fliQ and fliR genes encode highly hydrophobic polypeptides. The fliQ gene product, a small integral membrane protein that contains two putative transmembrane (TM) regions, is required for the assembly of the rivet at the earliest stage of flagellar biosynthesis.

Proteins sharing an evolutionary relationship with FliQ have been found in a range of bacteria: these include Yop translocation protein S from Yersinia pestis [PMID: 8300512]; surface antigen-presentation protein SpaQ from Salmonella typhimurium and Shigella flexneri [PMID: 8404849]; and probable translocation protein Y4YM from Rhizobium sp. (strain NGR234) [PMID: 9163424]. All of these members export proteins, that do not possess signal peptides, through the membrane. Although the proteins that these exporters move may be different, the exporters are thought to function in similar ways [PMID: 7814323].

GO terms

Biological Process

GO:0009306 protein secretion

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0016020 membrane

Contributing signatures

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