Crystal structures explain functional properties of two E. coli porins.
Porins form aqueous channels that aid the diffusion of small hydrophilic molecules across the outer membrane of Gram-negative bacteria. The crystal structures of matrix porin and phosphoporin both reveal trimers of identical subunits, each subunit consisting of a 16-stranded anti-parallel beta-barrel containing a pore. A long loop inside the barrel contributes to a constriction of the channel where the charge distribution affects ion selectivity. The structures explain at the molecular level functional characteristics and their alterations by known mutations.
Cowan
S W
SW
Department of Structural Biology, University of Basel, Switzerland.
Schirmer
T
T
Rummel
G
G
Steiert
M
M
Ghosh
R
R
Pauptit
R A
RA
Jansonius
J N
JN
Rosenbusch
J P
JP
D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000648:ultrastructure*; D003196:Computer Graphics; D003461:Crystallography; D004926:Escherichia coli / Q000648:ultrastructure*; D007473:Ion Channels / Q000502:physiology / Q000648:ultrastructure*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D018272:Porins; D011487:Protein Conformation; D012995:Solubility; D013329:Structure-Activity Relationship; D014867:Water; D014961:X-Ray Diffraction
D001425:Bacterial Outer Membrane Proteins; D007473:Ion Channels; D018272:Porins; D014867:Water