TY - JOUR
T1 - A large-conductance mechanosensitive channel in E. coli encoded by mscL alone
AU - Sukharev, Sergel I.
AU - Blount, Paul
AU - Martinac, Boris
AU - Blattner, Frederick R.
AU - Kung, Ching
PY - 1994
Y1 - 1994
N2 - ALL cellular organisms respond to vibration, touch, gravity or changes in osmolarity, although the molecules on which such mechanosensations depend are unknown. Candidates include certain channels that gate in response to membrane stretch1,2. Patch-clamp experiments with Escherichia coli envelope have revealed a mechanosensitive channel with very large conductance (MscL) and one with a smaller conductance (MscS)3-6 which may be important in osmoregulation. Here we have solubilized and fractionated the envelope, reconstituted the MscL activity in vitro, and traced it to a small protein, whose gene, mscL, we then cloned. Insertional disruption of mscL removes the channel activity, whereas re-expression of mscL borne on an expression plasmid restores it. MscL-channel activities were observed in material from a cell-free expression system with mscL as the only template. The mscL nucleotide sequence predicts a unique protein of only 136 amino acids, with a highly hydrophobic core and very different from porins or other known proteins.
AB - ALL cellular organisms respond to vibration, touch, gravity or changes in osmolarity, although the molecules on which such mechanosensations depend are unknown. Candidates include certain channels that gate in response to membrane stretch1,2. Patch-clamp experiments with Escherichia coli envelope have revealed a mechanosensitive channel with very large conductance (MscL) and one with a smaller conductance (MscS)3-6 which may be important in osmoregulation. Here we have solubilized and fractionated the envelope, reconstituted the MscL activity in vitro, and traced it to a small protein, whose gene, mscL, we then cloned. Insertional disruption of mscL removes the channel activity, whereas re-expression of mscL borne on an expression plasmid restores it. MscL-channel activities were observed in material from a cell-free expression system with mscL as the only template. The mscL nucleotide sequence predicts a unique protein of only 136 amino acids, with a highly hydrophobic core and very different from porins or other known proteins.
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U2 - 10.1038/368265a0
DO - 10.1038/368265a0
M3 - Article
C2 - 7511799
AN - SCOPUS:0028224356
SN - 0028-0836
VL - 368
SP - 265
EP - 268
JO - Nature
JF - Nature
IS - 6468
ER -