Escherichia coli K-12 substr. MG1655 Transporter: mechanosensitive channel MscS

Gene: mscS Accession Numbers: EG11160 (EcoCyc), b2924, ECK2920

Synonyms: yggB

Regulation Summary Diagram: ?

Regulation summary diagram for mscS

Subunit composition of mechanosensitive channel MscS = [MscS]7
         mechanosensitive channel MscS monomer = MscS

MscS is a mechanosensitive channel of small conductance; MscS conductance is 0.8-1 nanosiemens in E. coli giant protoplasts [Levina99].

MscS activity is adaptive, that is, it declines in response to sustained stimulation [Koprowski98]. In patch clamp experiments MscS activity occurs in short bursts that last for a few seconds [Levina99]. Gating of MscS is controlled by tension within, or voltage across the lipid bilayer [Sukharev93, Sukharev02]. Activation of MscS depends upon tension, while inactivation is both tension and voltage dependent; channel activation requires a high rate of increase in membrane tension; slower rates of increase can be ignored [Akitake05].

MscS is a homoheptamer [Bass02, Stenberg05]; with three transmembrane (TM) domains per subunit and a large cytoplasmic chamber [Bass02]. The N-terminus of each subunit forms a mixed helical hairpin structure located at the periplasmic interface of the lipid bilayer [Vasquez08]. The functional state represented in the crystal structure of [Bass02] - conducting [Spronk06] or non-conducting [Anishkin04, Sotomayor06, Sotomayor07] - is unclear. A model for closed [Vasquez08] and open [Anishkin08, Vasquez08a] conformations of MscS have been proposed.

The inhibition of MscS channel activity due to crosslinking of the C-terminus or adding Ni2+ to C-terminally, hexahistidine tagged proteins suggests that the C-terminus acts as a cytoplasmic gate and moves apart upon activation of the channel [Koprowski03]. Deletion of the C-terminus of MscS resulted in decreased stability and activity [Schumann04]. Crosslinking studies of cysteine substitutions reveal the very flexible architecture of the MscS channel and support the crystal structure and the prediction that MscS undergoes dramatic displacement of domains upon activation and deactivation [Miller03]. The structural rearrangements associated with MscS activation in membranes have been studied using functorial measurements, electron paramagnetic resonance (EPR) spectroscopy, and computational analyses [Vasquez08a].

Parabens induce MscS activity which allows leakage of cell contents, suggesting a mechanism for their antimicrobial activity [Nguyen05] although later experiments [Kamaraju08] suggest that MscS may not be the primary target for parabens. MscS is slightly anion-selective [Sukharev93].

The potassium dependent mechanosensitive channel MscK, contributes to small conductance channel activity in E. coli protoplasts but KefA channel activity does not desensitize on extended application of pressure; deletion of mscS eliminates the majority of small conductance channel activity [Levina99].

mscS expression is induced by RpoS upon entry into stationary phase and by osmotic stress [Stokes03].

Seven mechanosensitive ion channels have been characterised in E. coli K-12: MscL, MscS, MscK, MscM, YnaI, YbiO and YbdG. A strain lacking all seven of these proteins fails to demonstrate channel opening in patch clamp experiments [Edwards12].

mscS: mechanosensitive channel of small conductance

Reviews: [Edwards04, Booth99, Kubalski00, Martinac01, Pivetti03, Strop03, Perozo03, Bass03, Edwards04, Kung04]

Comments: [Sigrell76, Bezanilla02]

Citations: [Batiza02, Okada02, Kloda02, Li02b, Miller03a, Calladine03, Biggin03, Chiang04, Shapovalov04, Sotomayor04, Grajkowski05, Edwards05, Martinac05, Akitake07, Nomura06, Macdonald05]

Locations: inner membrane

Map Position: [3,066,969 <- 3,067,829] (66.1 centisomes, 238°)
Length: 861 bp / 286 aa

Molecular Weight of Polypeptide: 30.896 kD (from nucleotide sequence), 31.0 kD (experimental) [Sukharev02 ]

Unification Links: ASAP:ABE-0009595 , DIP:DIP-36192N , EchoBASE:EB1149 , EcoGene:EG11160 , EcoliWiki:b2924 , ModBase:P0C0S1 , OU-Microarray:b2924 , PortEco:mscS , PR:PRO_000023297 , Pride:P0C0S1 , Protein Model Portal:P0C0S1 , RefSeq:NP_417399 , RegulonDB:EG11160 , SMR:P0C0S1 , String:511145.b2924 , Swiss-Model:P0C0S1 , UniProt:P0C0S1

Relationship Links: InterPro:IN-FAMILY:IPR006685 , InterPro:IN-FAMILY:IPR006686 , InterPro:IN-FAMILY:IPR008910 , InterPro:IN-FAMILY:IPR010920 , InterPro:IN-FAMILY:IPR011014 , InterPro:IN-FAMILY:IPR011066 , PDB:Structure:2OAU , PDB:Structure:2VV5 , PDB:Structure:3UDC , PDB:Structure:4AGE , PDB:Structure:4AGF , PDB:Structure:4HWA , Pfam:IN-FAMILY:PF00924 , Pfam:IN-FAMILY:PF05552 , Prosite:IN-FAMILY:PS01246

In Paralogous Gene Group: 133 (3 members)

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Biological Process: GO:0009992 - cellular water homeostasis Inferred from experiment [Levina99]
GO:0034220 - ion transmembrane transport Inferred from experiment [Sukharev02]
GO:0006810 - transport Inferred by computational analysis [UniProtGOA11a]
GO:0006811 - ion transport Inferred by computational analysis [UniProtGOA11a]
GO:0055085 - transmembrane transport Inferred by computational analysis [GOA01a]
Molecular Function: GO:0008381 - mechanically-gated ion channel activity Inferred from experiment [Sukharev02]
Cellular Component: GO:0016021 - integral component of membrane Inferred from experiment Inferred by computational analysis [UniProtGOA11a, Sukharev02, Berrier89]
GO:0005886 - plasma membrane Inferred by computational analysis [UniProtGOA11, UniProtGOA11a, Berrier89]
GO:0016020 - membrane Inferred by computational analysis [UniProtGOA11a, GOA01a]

MultiFun Terms: cell processes adaptations other (mechanical, nutritional, oxidative stress)
cell structure membrane
transport Channel-type Transporters alpha-type channels

Essentiality data for mscS knockouts: ?

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
LB Lennox Yes 37 Aerobic 7   Yes [Baba06, Comment 1]
M9 medium with 1% glycerol Yes 37 Aerobic 7.2 0.35 Yes [Joyce06, Comment 2]
MOPS medium with 0.4% glucose Yes 37 Aerobic 7.2 0.22 Yes [Baba06, Comment 1]

Created 03-Oct-2007 by Johnson A , JCVI
Last-Curated ? 03-Oct-2007 by Johnson A , JCVI

Enzymatic reaction of: mechanosensitive channel MscS

Transport reaction diagram for mechanosensitive channel MscS

Sequence Features

Protein sequence of mechanosensitive channel MscS monomer with features indicated

Feature Class Location Common Name Citations Comment
Transmembrane-Region 29 -> 57 TM1
Mutagenesis-Variant 40  
[Okada02, UniProt15]
[Okada02, UniProt15]
V → C, G or N: No detectable phenotype.
V → D or K: Normal growth stops, without cell death, due to increased membrane permeability to potassium ions and protons (permeability tested only for D substitutions).
Mutagenesis-Variant 58  
[Miller03, UniProt15]
UniProt: Readily forms disulfide bonds with cross-linkers, suggesting that individual S-58 are only 3 Angstroms apart in the closed state, versus 33 Angstroms apart in the open state crystal structure.
Transmembrane-Region 68 -> 91 TM2
Transmembrane-Region 96 -> 113  
UniProt: Helical.
Transmembrane-Region 96 -> 127 TM3
Mutagenesis-Variant 266 -> 286  
[Edwards05, UniProt11]
[Edwards05, UniProt11]
ISFPYPQMDVNFKRVKEDKAA → LE: Fewer channels present in the membrane, they require slightly more pressure to open and do not recover after desensitization.
ISFPYPQMDVNFKRVKEDKAA → HHHHHHLE: Normal levels of channels are expressed; they recover more slowly than wild-type cells after desensitization.
Mutagenesis-Variant 267  
[Miller03, UniProt15]
UniProt: Provides biochemical evidence for heptameric structure upon cross-linking.

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Unit:

Transcription-unit diagram


10/20/97 Gene b2924 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG11160; confirmed by SwissProt match.


Akitake05: Akitake B, Anishkin A, Sukharev S (2005). "The "dashpot" mechanism of stretch-dependent gating in MscS." J Gen Physiol 125(2);143-54. PMID: 15657299

Akitake07: Akitake B, Spelbrink RE, Anishkin A, Killian JA, de Kruijff B, Sukharev S (2007). "2,2,2-Trifluoroethanol changes the transition kinetics and subunit interactions in the small bacterial mechanosensitive channel MscS." Biophys J 92(8);2771-84. PMID: 17277184

Anishkin04: Anishkin A, Sukharev S (2004). "Water dynamics and dewetting transitions in the small mechanosensitive channel MscS." Biophys J 86(5);2883-95. PMID: 15111405

Anishkin08: Anishkin A, Kamaraju K, Sukharev S (2008). "Mechanosensitive channel MscS in the open state: modeling of the transition, explicit simulations, and experimental measurements of conductance." J Gen Physiol 132(1);67-83. PMID: 18591417

Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554

Bass02: Bass RB, Strop P, Barclay M, Rees DC (2002). "Crystal structure of Escherichia coli MscS, a voltage-modulated and mechanosensitive channel." Science 298(5598);1582-7. PMID: 12446901

Bass03: Bass RB, Locher KP, Borths E, Poon Y, Strop P, Lee A, Rees DC (2003). "The structures of BtuCD and MscS and their implications for transporter and channel function." FEBS Lett 555(1);111-5. PMID: 14630329

Batiza02: Batiza AF, Kuo MM, Yoshimura K, Kung C (2002). "Gating the bacterial mechanosensitive channel MscL invivo." Proc Natl Acad Sci U S A 99(8);5643-8. PMID: 11960017

Berrier89: Berrier C, Coulombe A, Houssin C, Ghazi A (1989). "A patch-clamp study of ion channels of inner and outer membranes and of contact zones of E. coli, fused into giant liposomes. Pressure-activated channels are localized in the inner membrane." FEBS Lett 259(1);27-32. PMID: 2480919

Bezanilla02: Bezanilla F, Perozo E (2002). "Structural biology. Force and voltage sensors in one structure." Science 298(5598);1562-3. PMID: 12446894

Biggin03: Biggin PC, Sansom MS (2003). "Mechanosensitive channels: stress relief." Curr Biol 13(5);R183-5. PMID: 12620208

Booth99: Booth IR, Louis P (1999). "Managing hypoosmotic stress: aquaporins and mechanosensitive channels in Escherichia coli." Curr Opin Microbiol 2(2);166-9. PMID: 10322175

Calladine03: Calladine CR, Pratap V, Chandran V, Mizuguchi K, Luisi BF (2003). "Cylindrical channels from concave helices." Science 299(5607);661-2. PMID: 12561825

Chiang04: Chiang CS, Anishkin A, Sukharev S (2004). "Gating of the large mechanosensitive channel in situ: estimation of the spatial scale of the transition from channel population responses." Biophys J 86(5);2846-61. PMID: 15111402

Edwards04: Edwards MD, Booth IR, Miller S (2004). "Gating the bacterial mechanosensitive channels: MscS a new paradigm?." Curr Opin Microbiol 7(2);163-7. PMID: 15063854

Edwards05: Edwards MD, Li Y, Kim S, Miller S, Bartlett W, Black S, Dennison S, Iscla I, Blount P, Bowie JU, Booth IR (2005). "Pivotal role of the glycine-rich TM3 helix in gating the MscS mechanosensitive channel." Nat Struct Mol Biol 12(2);113-9. PMID: 15665866

Edwards12: Edwards MD, Black S, Rasmussen T, Rasmussen A, Stokes NR, Stephen TL, Miller S, Booth IR (2012). "Characterization of three novel mechanosensitive channel activities in Escherichia coli." Channels (Austin) 6(4);272-81. PMID: 22874652

GOA01a: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

Grajkowski05: Grajkowski W, Kubalski A, Koprowski P (2005). "Surface changes of the mechanosensitive channel MscS upon its activation, inactivation, and closing." Biophys J 88(4);3050-9. PMID: 15665126

Joyce06: Joyce AR, Reed JL, White A, Edwards R, Osterman A, Baba T, Mori H, Lesely SA, Palsson BO, Agarwalla S (2006). "Experimental and computational assessment of conditionally essential genes in Escherichia coli." J Bacteriol 188(23);8259-71. PMID: 17012394

Kamaraju08: Kamaraju K, Sukharev S (2008). "The membrane lateral pressure-perturbing capacity of parabens and their effects on the mechanosensitive channel directly correlate with hydrophobicity." Biochemistry 47(40);10540-50. PMID: 18795793

Kloda02: Kloda A, Martinac B (2002). "Mechanosensitive channels of bacteria and archaea share a common ancestral origin." Eur Biophys J 31(1);14-25. PMID: 12046893

Koprowski03: Koprowski P, Kubalski A (2003). "C termini of the Escherichia coli mechanosensitive ion channel (MscS) move apart upon the channel opening." J Biol Chem 278(13);11237-45. PMID: 12551944

Koprowski98: Koprowski P, Kubalski A (1998). "Voltage-independent adaptation of mechanosensitive channels in Escherichia coli protoplasts." J Membr Biol 164(3);253-62. PMID: 9691118

Kubalski00: Kubalski A, Koprowski P (2000). "[Bacterial ion canals]." Postepy Hig Med Dosw 54(3);317-27. PMID: 10941266

Kung04: Kung C, Blount P (2004). "Channels in microbes: so many holes to fill." Mol Microbiol 53(2);373-80. PMID: 15228520

Levina99: Levina N, Totemeyer S, Stokes NR, Louis P, Jones MA, Booth IR (1999). "Protection of Escherichia coli cells against extreme turgor by activation of MscS and MscL mechanosensitive channels: identification of genes required for MscS activity." EMBO J 1999;18(7);1730-7. PMID: 10202137

Li02b: Li Y, Moe PC, Chandrasekaran S, Booth IR, Blount P (2002). "Ionic regulation of MscK, a mechanosensitive channel from Escherichia coli." EMBO J 21(20);5323-30. PMID: 12374733

Macdonald05: Macdonald AG, Martinac B (2005). "Effect of high hydrostatic pressure on the bacterial mechanosensitive channel MscS." Eur Biophys J 34(5);434-41. PMID: 15834558

Martinac01: Martinac B (2001). "Mechanosensitive channels in prokaryotes." Cell Physiol Biochem 11(2);61-76. PMID: 11275684

Martinac05: Martinac B (2005). "Structural plasticity in MS channels." Nat Struct Mol Biol 12(2);104-5. PMID: 15702067

Miller03: Miller S, Edwards MD, Ozdemir C, Booth IR (2003). "The closed structure of the MscS mechanosensitive channel. Cross-linking of single cysteine mutants." J Biol Chem 278(34);32246-50. PMID: 12767977

Miller03a: Miller S, Bartlett W, Chandrasekaran S, Simpson S, Edwards M, Booth IR (2003). "Domain organization of the MscS mechanosensitive channel of Escherichia coli." EMBO J 22(1);36-46. PMID: 12505982

Nguyen05: Nguyen T, Clare B, Guo W, Martinac B (2005). "The effects of parabens on the mechanosensitive channels of E. coli." Eur Biophys J 34(5);389-95. PMID: 15770478

Nomura06: Nomura T, Sokabe M, Yoshimura K (2006). "Lipid-protein interaction of the MscS mechanosensitive channel examined by scanning mutagenesis." Biophys J 91(8);2874-81. PMID: 16861270

Okada02: Okada K, Moe PC, Blount P (2002). "Functional design of bacterial mechanosensitive channels. Comparisons and contrasts illuminated by random mutagenesis." J Biol Chem 277(31);27682-8. PMID: 12015316

Perozo03: Perozo E, Rees DC (2003). "Structure and mechanism in prokaryotic mechanosensitive channels." Curr Opin Struct Biol 13(4);432-42. PMID: 12948773

Pivetti03: Pivetti CD, Yen MR, Miller S, Busch W, Tseng YH, Booth IR, Saier MH (2003). "Two families of mechanosensitive channel proteins." Microbiol Mol Biol Rev 67(1);66-85, table of contents. PMID: 12626684

Schumann04: Schumann U, Edwards MD, Li C, Booth IR (2004). "The conserved carboxy-terminus of the MscS mechanosensitive channel is not essential but increases stability and activity." FEBS Lett 572(1-3);233-7. PMID: 15304354

Shapovalov04: Shapovalov G, Lester HA (2004). "Gating transitions in bacterial ion channels measured at 3 microns resolution." J Gen Physiol 124(2);151-61. PMID: 15277576

Sigrell76: Sigrell B (1976). "[Psychotherapy--an educative process]." Lakartidningen 73(9);721-3. PMID: 1256182

Sotomayor04: Sotomayor M, Schulten K (2004). "Molecular dynamics study of gating in the mechanosensitive channel of small conductance MscS." Biophys J 87(5);3050-65. PMID: 15339798

Sotomayor06: Sotomayor M, van der Straaten TA, Ravaioli U, Schulten K (2006). "Electrostatic properties of the mechanosensitive channel of small conductance MscS." Biophys J 90(10);3496-510. PMID: 16513774

Sotomayor07: Sotomayor M, Vasquez V, Perozo E, Schulten K (2007). "Ion conduction through MscS as determined by electrophysiology and simulation." Biophys J 92(3);886-902. PMID: 17114233

Spronk06: Spronk SA, Elmore DE, Dougherty DA (2006). "Voltage-dependent hydration and conduction properties of the hydrophobic pore of the mechanosensitive channel of small conductance." Biophys J 90(10);3555-69. PMID: 16500980

Stenberg05: Stenberg F, Chovanec P, Maslen SL, Robinson CV, Ilag LL, von Heijne G, Daley DO (2005). "Protein complexes of the Escherichia coli cell envelope." J Biol Chem 280(41);34409-19. PMID: 16079137

Stokes03: Stokes NR, Murray HD, Subramaniam C, Gourse RL, Louis P, Bartlett W, Miller S, Booth IR (2003). "A role for mechanosensitive channels in survival of stationary phase: regulation of channel expression by RpoS." Proc Natl Acad Sci U S A 100(26);15959-64. PMID: 14671322

Strop03: Strop P, Bass R, Rees DC (2003). "Prokaryotic mechanosensitive channels." Adv Protein Chem 63;177-209. PMID: 12629971

Sukharev02: Sukharev S (2002). "Purification of the small mechanosensitive channel of Escherichia coli (MscS): the subunit structure, conduction, and gating characteristics in liposomes." Biophys J 83(1);290-8. PMID: 12080120

Sukharev93: Sukharev SI, Martinac B, Arshavsky VY, Kung C (1993). "Two types of mechanosensitive channels in the Escherichia coli cell envelope: solubilization and functional reconstitution." Biophys J 65(1);177-83. PMID: 7690260

UniProt11: UniProt Consortium (2011). "UniProt version 2011-06 released on 2011-06-30 00:00:00." Database.

UniProt15: UniProt Consortium (2015). "UniProt version 2015-01 released on 2015-01-16 00:00:00." Database.

UniProtGOA11: UniProt-GOA (2011). "Gene Ontology annotation based on the manual assignment of UniProtKB Subcellular Location terms in UniProtKB/Swiss-Prot entries."

UniProtGOA11a: UniProt-GOA (2011). "Gene Ontology annotation based on manual assignment of UniProtKB keywords in UniProtKB/Swiss-Prot entries."

Vasquez08: Vasquez V, Sotomayor M, Cortes DM, Roux B, Schulten K, Perozo E (2008). "Three-dimensional architecture of membrane-embedded MscS in the closed conformation." J Mol Biol 378(1);55-70. PMID: 18343404

Vasquez08a: Vasquez V, Sotomayor M, Cordero-Morales J, Schulten K, Perozo E (2008). "A structural mechanism for MscS gating in lipid bilayers." Science 321(5893);1210-4. PMID: 18755978

Other References Related to Gene Regulation

MendozaVargas09: Mendoza-Vargas A, Olvera L, Olvera M, Grande R, Vega-Alvarado L, Taboada B, Jimenez-Jacinto V, Salgado H, Juarez K, Contreras-Moreira B, Huerta AM, Collado-Vides J, Morett E (2009). "Genome-wide identification of transcription start sites, promoters and transcription factor binding sites in E. coli." PLoS One 4(10);e7526. PMID: 19838305

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
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