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PDBsum entry 2f1v
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Membrane protein
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PDB id
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2f1v
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References listed in PDB file
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Key reference
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Title
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The outer membrane protein ompw forms an eight-Stranded beta-Barrel with a hydrophobic channel.
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Authors
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H.Hong,
D.R.Patel,
L.K.Tamm,
B.Van den berg.
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Ref.
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J Biol Chem, 2006,
281,
7568-7577.
[DOI no: ]
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PubMed id
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Abstract
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Escherichia coli OmpW belongs to a family of small outer membrane proteins that
are widespread in Gram-negative bacteria. Their functions are unknown, but
recent data suggest that they may be involved in the protection of bacteria
against various forms of environmental stress. To gain insight into the function
of these proteins A we have determined the crystal structure of E. coli OmpW to
2.7-A resolution. The structure shows that OmpW forms an 8-stranded beta-barrel
with a long and narrow hydrophobic channel that contains a bound
n-dodecyl-N,N-dimethylamine-N-oxide detergent molecule. Single channel
conductance experiments show that OmpW functions as an ion channel in planar
lipid bilayers. The channel activity can be blocked by the addition of
n-dodecyl-N,N-dimethylamine-N-oxide. Taken together, the data suggest that
members of the OmpW family could be involved in the transport of small
hydrophobic molecules across the bacterial outer membrane.
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Figure 1.
FIGURE 1. Schematic overview of the OmpW structure. A and
B, ribbon diagrams viewed from the side, with B, 90° rotated
relative to A. Extracellular loops (L) and periplasmic turns (T)
are indicated. The N terminus in B is indicated with N, and the
C terminus is indicated with C. The  -strands are numbered
from S1 to S8. The position of the opening in the barrel wall
between strands S3 and S4 is indicated with an asterisk (^*).
The approximate boundary of the hydrophobic part of the OM is
indicated with horizontal lines, with out being the
extracellular environment and in the periplasmic space. C, view
of OmpW from the extracellular side, showing the ellipsoid shape
of the barrel. The positions of several loops are indicated.
Figs. 1, 3, and 8 were generated with PYMOL (40).
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Figure 4.
FIGURE 4. Representative single channel recordings of OmpW,
OmpA, and Tsx in planar diphytanoyl-PC lipid bilayers in 1 M KCl
at pH 7 and +140 mV. Proteins were reconstituted from C[8]E[4]
detergent micelles or DPPC (DPoPC) proteoliposomes as indicated.
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The above figures are
reprinted
by permission from the ASBMB:
J Biol Chem
(2006,
281,
7568-7577)
copyright 2006.
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