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1.A.23.1.1
Minor K+-dependent MscS-type mechanosensitive channel protein, designated KefA, AefA or MscK, (Edwards et al. 2012). A molecular dynamics study of gating has been published (Sotomayor and Schulten 2004). It suggested that when restraining the backbone of the protein, the channel remained in the open form and the simulation revealed intermittent permeation of water molecules through the channel. Abolishing the restraints under constant pressure conditions led to spontaneous closure of the transmembrane channel, whereas abolishing the restraints when surface tension (20 dyn/cm) was applied led to channel widening. The large balloon-shaped cytoplasmic domain of MscS exhibited spontaneous diffusion of ions through its side openings. Interaction between the transmembrane domain and the cytoplasmic domain of MscS was observed and involved formation of salt bridges between residues Asp62 and Arg128; this interaction may be essential for the gating of MscS. K+ and Cl- ions showed distinctively different distributions in and around the channel (Sotomayor and Schulten 2004).

Accession Number:P77338
Protein Name:KefA aka AEFA aka B0465
Length:1120
Molecular Weight:127215.00
Species:Escherichia coli [83333]
Number of TMSs:11
Location1 / Topology2 / Orientation3: Cell inner membrane1 / Multi-pass membrane protein2
Substrate ions

Cross database links:

Genevestigator: P77338
EchoBASE: EB3991
EcoGene: EG14240
eggNOG: COG3264
HEGENOM: HBG296859
DIP: DIP-10070N
RefSeq: AP_001114.1    NP_414998.1   
Entrez Gene ID: 945132   
Pfam: PF00924   
BioCyc: EcoCyc:G6255-MONOMER    ECOL168927:B0465-MONOMER   
KEGG: ecj:JW0454    eco:b0465   

Gene Ontology

GO:0016021 C:integral to membrane
GO:0005886 C:plasma membrane
GO:0008381 F:mechanically-gated ion channel activity
GO:0009992 P:cellular water homeostasis
GO:0006813 P:potassium ion transport
GO:0055085 P:transmembrane transport

References (4)

[1] “The complete genome sequence of Escherichia coli K-12.”  Blattner F.R.et.al.   9278503
[2] “Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 and W3110.”  Hayashi K.et.al.   16738553
[3] “Protection of Escherichia coli cells against extreme turgor by activation of MscS and MscL mechanosensitive channels: identification of genes required for MscS activity.”  Levina N.et.al.   10202137
[4] “Global topology analysis of the Escherichia coli inner membrane proteome.”  Daley D.O.et.al.   15919996

External Searches:

  • Search: DB with
  • BLAST ExPASy (Swiss Institute of Bioinformatics (SIB) BLAST)
  • CDD Search (Conserved Domain Database)
  • Search COGs (Clusters of Orthologous Groups of proteins)
  • 2° Structure (Network Protein Sequence Analysis)

Analyze:

Predict TMSs (Predict number of transmembrane segments)
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FASTA formatted sequence
1:	MTMFQYYKRS RHFVFSAFIA FVFVLLCQNT AFARASSNGD LPTKADLQAQ LDSLNKQKDL 
61:	SAQDKLVQQD LTDTLATLDK IDRIKEETVQ LRQKVAEAPE KMRQATAALT ALSDVDNDEE 
121:	TRKILSTLSL RQLETRVAQA LDDLQNAQND LASYNSQLVS LQTQPERVQN AMYNASQQLQ 
181:	QIRSRLDGTD VGETALRPSQ KVLMQAQQAL LNAEIDQQRK SLEGNTVLQD TLQKQRDYVT 
241:	ANSARLEHQL QLLQEAVNSK RLTLTEKTAQ EAVSPDEAAR IQANPLVKQE LEINQQLSQR 
301:	LITATENGNQ LMQQNIKVKN WLERALQSER NIKEQIAVLK GSLLLSRILY QQQQTLPSAD 
361:	ELENMTNRIA DLRLEQFEVN QQRDALFQSD AFVNKLEEGH TNEVNSEVHD ALLQVVDMRR 
421:	ELLDQLNKQL GNQLMMAINL QINQQQLMSV SKNLKSILTQ QIFWVNSNRP MDWDWIKAFP 
481:	QSLKDEFKSM KITVNWQKAW PAVFIAFLAG LPLLLIAGLI HWRLGWLKAY QQKLASAVGS 
541:	LRNDSQLNTP KAILIDLIRA LPVCLIILAV GLILLTMQLN ISELLWSFSK KLAIFWLVFG 
601:	LCWKVLEKNG VAVRHFGMPE QQTSHWRRQI VRISLALLPI HFWSVVAELS PLHLMDDVLG 
661:	QAMIFFNLLL IAFLVWPMCR ESWRDKESHT MRLVTITVLS IIPIALMVLT ATGYFYTTLR 
721:	LAGRWIETVY LVIIWNLLYQ TVLRGLSVAA RRIAWRRALA RRQNLVKEGA EGAEPPEEPT 
781:	IALEQVNQQT LRITMLLMFA LFGVMFWAIW SDLITVFSYL DSITLWHYNG TEAGAAVVKN 
841:	VTMGSLLFAI IASMVAWALI RNLPGLLEVL VLSRLNMRQG ASYAITTILN YIIIAVGAMT 
901:	VFGSLGVSWD KLQWLAAALS VGLGFGLQEI FGNFVSGLII LFERPVRIGD TVTIGSFSGT 
961:	VSKIRIRATT ITDFDRKEVI IPNKAFVTER LINWSLTDTT TRLVIRLGVA YGSDLEKVRK 
1021:	VLLKAATEHP RVMHEPMPEV FFTAFGASTL DHELRLYVRE LRDRSRTVDE LNRTIDQLCR 
1081:	ENDINIAFNQ LEVHLHNEKG DEVTEVKRDY KGDDPTPAVG