Small-conductance mechanosensitive channel
| MS_channel | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | MS_channel | ||||||||
| Pfam | PF00924 | ||||||||
| InterPro | IPR006685 | ||||||||
| PROSITE | PDOC00959 | ||||||||
| SCOP | 1mxm | ||||||||
| SUPERFAMILY | 1mxm | ||||||||
| TCDB | 1.A.23 | ||||||||
| OPM superfamily | 11 | ||||||||
| OPM protein | 2vv5 | ||||||||
| |||||||||
Mechanosensitive (MS) channels provide protection against hypo-osmotic shock, responding both to stretching of the cell membrane and to membrane depolarisation. They are present in the membranes of organisms from the three domains of life: bacteria, archaea, and eukarya.[1] There are two families of MS channels: large-conductance MS channels (MscL) and small-conductance MS channels (MscS or YGGB). The pressure threshold for MscS opening is 50% that of MscL.[2] The MscS family is much larger and more variable in size and sequence than the MscL family. Much of the diversity in MscS proteins occurs in the size of the transmembrane regions, which ranges from three to eleven transmembrane helices, although the three C-terminal helices are conserved. This family contains sequences form the MscS family of proteins.
MscS folds as a homo-heptamer with a cylindrical shape, and can be divided into transmembrane and extramembrane regions: an N-terminal periplasmic region, a transmembrane region, and a C-terminal cytoplasmic region (middle and C-terminal domains). The transmembrane region forms a channel through the membrane that opens into a chamber enclosed by the extramembrane portion, the latter connecting to the cytoplasm through distinct portals.[2]
References
- ↑ Pivetti CD, Yen MR, Miller S, Busch W, Tseng YH, Booth IR, Saier MH (March 2003). "Two families of mechanosensitive channel proteins". Microbiol. Mol. Biol. Rev. 67 (1): 66–85, table of contents. doi:10.1128/MMBR.67.1.66-85.2003. PMC 150521. PMID 12626684.
- 1 2 Bass RB, Strop P, Barclay M, Rees DC (November 2002). "Crystal structure of Escherichia coli MscS, a voltage-modulated and mechanosensitive channel". Science 298 (5598): 1582–7. doi:10.1126/science.1077945. PMID 12446901.
This article incorporates text from the public domain Pfam and InterPro IPR006685