InterPro : IPR023201

Name  SecY subunit domain Short Name  SecY_su_dom
Type  Domain 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 (SecY, 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 []. The structure of the Escherichia coliSecYEG assembly revealed a sandwich of two membranesinteracting through the extensive cytoplasmic domains []. Each membrane is composed of dimers of SecYEG. Themonomeric complex contains 15 transmembrane helices. The eubacterial secY protein []interacts with the signal sequences of secretory proteins as well as with two other components of the protein translocation system: secA and secE. SecY is an integral plasma membrane protein of 419 to 492 amino acid residues that apparently contains 10 transmembrane (TM), 6 cytoplasmic and 5 periplasmic regions. Cytoplasmic regions 2 and 3, and TM domains 1, 2, 4, 5, 7 and 10 are well conserved: the conserved cytoplasmic regions are believed to interact with cytoplasmic secretion factors, while the TM domains may participate in protein export []. Homologs of secY are found in archaebacteria []. SecY is also encoded in the chloroplast genome of some algae []where it could be involved in a prokaryotic-like protein export system across the two membranes of the chloroplast endoplasmic reticulum (CER) which is present in chromophyte and cryptophyte algae.This entry represents the structural domain of SecY [].

Sequence Features

GO Displayer


InterPro protein domain ID --> Contigs



0 Child Features

0 Contains

0 Found In

0 Parent Features

9 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
Auer J Presence of a gene in the archaebacterium Methanococcus vannielii homologous to secY of eubacteria. 1991 Biochimie 73 683-8
Douglas SE A secY homologue is found in the plastid genome of Cryptomonas phi. 1992 FEBS Lett 298 93-6
Suh JW Isolation of a secY homologue from Bacillus subtilis: evidence for a common protein export pathway in eubacteria. 1990 Mol Microbiol 4 305-14
Ito K SecY and integral membrane components of the Escherichia coli protein translocation system. 1992 Mol Microbiol 6 2423-8
Breyton C Three-dimensional structure of the bacterial protein-translocation complex SecYEG. 2002 Nature 418 662-5
Van den Berg B X-ray structure of a protein-conducting channel. 2004 Nature 427 36-44

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)