3.A.14 The Fimbrilin/Protein Exporter (FPE) Family

Each of the protein exporters in the FPE family consists of two constituents, an integral membrane protein having 320-420 amino acyl residues and 3 putative TMSs, and an ATPase localized to the cytoplasmic side of the membrane and having 350-570 amino acyl residues and Walker ATP binding motifs. These proteins are believed to function together in the ATP-hydrolysis-dependent export of proteins across the cytoplasmic membranes of Gram-positive and Gram-negative bacteria. Some of these proteins are homologous to proteins required for export of substrate proteins across the outer membranes of Gram-negative bacteria via the main terminal branch (TC #3.A.15). Briley et al. (2011) have shown that the secretion ATPase ComGA is required for the binding and transport of transforming DNA.

The generalized transport reaction believed to be catalyzed by FPE systems is:

Protein (in) + ATP → Protein (out) + ADP + Pi



Briley, K., Jr, A. Dorsey-Oresto, P. Prepiak, M.J. Dias, J.M. Mann, and D. Dubnau. (2011). The secretion ATPase ComGA is required for the binding and transport of transforming DNA. Mol. Microbiol. 81: 818-830.

Chung, Y.S., F. Breidt, and D. Dubnau. (1998). Cell surface localization and processing of the ComG proteins, required for DNA binding during transformation of Bacillus subtilis. Mol. Microbiol. 29: 905-913.

Dubnau, D. (1997). Binding and transport of transforming DNA by Bacillus subtilis: the role of type-IV pilin-like proteins–a review. Gene 192: 191-198.

Rabinovich, L., N. Sigal, I. Borovok, R. Nir-Paz, and A.A. Herskovits. (2012). Prophage Excision Activates Listeria Competence Genes that Promote Phagosomal Escape and Virulence. Cell 150: 792-802.

Tjalsma H., A. Bolhuis, J.D. Jongbloed, S. Bron, and J.M. van Dijl. (2000). Signal peptide-dependent protein transport in Bacillus subtilis: a genome-based survey of the secretome. Microbiol. Mol. Biol. Rev. 64: 515-547.


TC#NameOrganismal TypeExample
3.A.14.1.1The competence-related pilin exporter, ComGA/GB Bacteria ComGA/GB of Bacillus subtilis

ComGA (G2JS07). The phagosome escape and virulence competence system-related pilin exporter, ComGA/GB. Exports pseudopilus ComGC-ComGG (Rabinovich et al., 2012). Functions in conjunction with 3.A.11.1.4.


ComGA - GG of Listeria monocytogenes
ComGA (G2JS07)
ComGB (G2JS06)
ComGC (G2JS05) 
ComGD (G2JS04) 
ComGE (G2JS03)
ComGF (G2JS02) 
ComGG (G2JS01)