InterPro : IPR003708

Name  Bacterial protein export chaperone SecB Short Name  SecB
Type  Family Description  Secretion across the inner membrane in some Gram-negative bacteria occursvia thepreprotein translocase pathway. Proteins are produced in the cytoplasm as precursors, and require a chaperone subunit to direct them to the translocase component []. From there, the mature proteins are either targeted to the outer membrane, or remain as periplasmic proteins. The translocase protein subunits are encoded on the bacterial chromosome.The translocase itself comprises 7 proteins, including a chaperone protein(SecB), an ATPase (SecA), an integral membrane complex (SecCY, SecE and SecG), and two additional membrane proteins that promote the release of the mature peptide into the periplasm (SecD and SecF) []. The chaperone protein SecB []is a highly acidic homotetrameric protein that existsas a "dimer of dimers" in the bacterial cytoplasm. SecB maintains preproteins in an unfolded state after translation, and targets these to the peripheral membrane protein ATPase SecA for secretion [].Recently, the tertiary structure of Haemophilus influenzaeSecB () was resolvedby means of X-ray crystallography to 2.5A []. The chaperone comprises fourchains, forming a tetramer, each chain of which has a simple alpha+beta foldarrangement. While one binding site on the homotetramer recognises unfoldedpolypeptides by hydrophobic interactions, the second binds to SecA throughthe latter's C-terminal 22 residues.

Sequence Features

GO Displayer


InterPro protein domain ID --> Contigs



0 Child Features

0 Contains

0 Found In

0 Parent Features

4 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
Xu Z Crystal structure of the bacterial protein export chaperone secB. 2000 Nat Struct Biol 7 1172-7

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)