Member database | PROSITE patterns |
PROSITE patterns type | conserved site |
Short name | SECY_1 |
Description
The eubacterial secY protein
[3] plays an important role in protein export. It
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 ten transmembrane segments. Such a structure probably
confers to secY a 'translocator' function, providing a channel for periplasmic
and outer-membrane precursor proteins.
Homologs of secY are found in archaebacteria
[2]. SecY is also encoded in
the chloroplast genome of some algae
[4] 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.
In eukaryotes, the evolutionary related protein sec61-alpha plays a role in
protein translocation through the endoplasmic reticulum; it is part of a
trimeric complex that also consist of sec61-beta and gamma
[1].
We have developed two signature patterns for secY proteins. The first
corresponds to the second transmembrane region, which is the most conserved
section of these proteins. The second spans the C-terminal part of the fourth
transmembrane region, a short intracellular loop, and the N-terminal part of
the fifth transmembrane region.
References
1.Evolutionary conservation of components of the protein translocation complex. Hartmann E, Sommer T, Prehn S, Gorlich D, Jentsch S, Rapoport TA. Nature 367, 654-7, (1994). View articlePMID: 8107851
2.Presence of a gene in the archaebacterium Methanococcus vannielii homologous to secY of eubacteria. Auer J, Spicker G, Bock A. Biochimie 73, 683-8, (1991). View articlePMID: 1764515
3.SecY and integral membrane components of the Escherichia coli protein translocation system. Ito K. Mol. Microbiol. 6, 2423-8, (1992). PMID: 1406280
4.A secY homologue is found in the plastid genome of Cryptomonas phi. Douglas SE. FEBS Lett. 298, 93-6, (1992). View articlePMID: 1544427