InterPro : IPR022645

Name  Protein-export membrane protein SecD/SecF, bacterial Short Name  SecD/SecF_bac
Type  Family Description  Secretion across the inner membrane in some Gram-negative bacteria occurs via the preprotein translocasepathway. Proteins are produced in the cytoplasm as precursors, and require a chaperone subunit to direct them tothe translocase component []. From there, the mature proteins are either targeted to the outermembrane, or remain as periplasmic proteins. The translocase protein subunits are encoded on the bacterialchromosome. The translocase itself comprises 7 proteins, including a chaperone protein (SecB), an ATPase (SecA), an integralmembrane complex (SecCY, SecE and SecG), and two additional membrane proteins that promote the release ofthe mature peptide into the periplasm (SecD and SecF) []. The chaperone protein SecB []is a highly acidic homotetrameric protein that exists as a "dimer of dimers" in the bacterial cytoplasm.SecB maintains preproteins in an unfolded state after translation, and targets these to the peripheral membraneprotein ATPase SecA for secretion []. Together with SecY and SecG, SecE forms a multimericchannel through which preproteins are translocated, using both proton motive forces and ATP-driven secretion. Thelatter is mediated by SecA. The structure of theEscherichia coliSecYEG assembly revealed a sandwich of two membranes interacting through the extensive cytoplasmicdomains []. Each membrane is composed of dimers of SecYEG. The monomeric complex contains 15transmembrane helices. The SecD and SecF equivalents of theGram-positive bacterium Bacillus subtilisare jointly present in one polypeptide,denoted SecDF, that is required to maintain a high capacity for protein secretion.Unlike the SecD subunit of the pre-protein translocase of E. coli, SecDFof B. subtilis was not required for the release of a mature secretory protein fromthe membrane, indicating that SecDF is involved in earlier translocation steps [].Comparison with SecD andSecF proteins from other organisms revealed the presence of 10 conservedregions in SecDF, some of which appear to be important for SecDF function.Interestingly, the SecDF protein of B. subtilis has 12 putative transmembranedomains. Thus, SecDF does not only show sequence similarity but also structuralsimilarity to secondary solute transporters [].This entry represents bacterial SecD and SecF protein export membrane proteins. It is found in association with SecD and SecF proteins are part of the multimeric protein export complex comprising SecA, D, E, F, G, Y, and YajC []. SecD and SecF are required to maintain a proton motive force [].

Sequence Features

GO Displayer


InterPro protein domain ID --> Contigs



2 Child Features

Id Name Short Name Type
IPR005665 Protein-export membrane protein SecF, bacterial SecF_bac Family
IPR005791 Protein translocase subunit SecD SecD Family

0 Contains

0 Found In

1 Parent Features

Id Name Short Name Type
IPR022813 Protein-export membrane protein SecD/SecF, archaeal and bacterial SecD/SecF_arch_bac Family

6 Publications

First Author Title Year Journal Volume Pages
Bieker KL The sec and prl genes of Escherichia coli. 1990 J Bioenerg Biomembr 22 291-310
Driessen AJ SecB, a molecular chaperone with two faces. 2001 Trends Microbiol 9 193-6
Müller JP Effects of pre-protein overexpression on SecB synthesis in Escherichia coli. 1999 FEMS Microbiol Lett 176 219-27
Breyton C Three-dimensional structure of the bacterial protein-translocation complex SecYEG. 2002 Nature 418 662-5
Bolhuis A SecDF of Bacillus subtilis, a molecular Siamese twin required for the efficient secretion of proteins. 1998 J Biol Chem 273 21217-24
Arkowitz RA SecD and SecF are required for the proton electrochemical gradient stimulation of preprotein translocation. 1994 EMBO J 13 954-63

To cite PlanMine, please refer to the following publication:

Rozanski, A., Moon, H., Brandl, H., Martín-Durán, J. M., Grohme, M., Hüttner, K., Bartscherer, K., Henry, I., & Rink, J. C.
PlanMine 3.0—improvements to a mineable resource of flatworm biology and biodiversity
Nucleic Acids Research, gky1070. doi:10.1093/nar/gky1070 (2018)