TY - JOUR
T1 - TonB-dependent receptors - Structural perspectives
AU - Ferguson, Andrew D.
AU - Deisenhofer, Johann
N1 - Funding Information:
This work was financially supported by the Welch Foundation, Canadian Institute of Health Research, and the Human Frontier of Science Program.
PY - 2002/10/11
Y1 - 2002/10/11
N2 - Plants, bacteria, fungi, and yeast utilize organic iron chelators (siderophores) to establish commensal and pathogenic relationships with hosts and to survive as free-living organisms. In Gram-negative bacteria, transport of siderophores into the periplasm is mediated by TonB-dependent receptors. A complex of three membrane-spanning proteins TonB, ExbB and ExbD couples the chemiosmotic potential of the cytoplasmic membrane with siderophore uptake across the outer membrane. The crystallographic structures of two TonB-dependent receptors (FhuA and FepA) have recently been determined. These outer membrane transporters show a novel fold consisting of two domains. A 22-stranded antiparallel β-barrel traverses the outer membrane and adjacent β-strands are connected by extracellular loops and periplasmic turns. Located inside the β-barrel is the plug domain, composed primarily of a mixed four-stranded β-sheet and a series of interspersed α-helices. Siderophore binding induces distinct local and allosteric transitions that establish the structural basis of signal transduction across the outer membrane and suggest a transport mechanism.
AB - Plants, bacteria, fungi, and yeast utilize organic iron chelators (siderophores) to establish commensal and pathogenic relationships with hosts and to survive as free-living organisms. In Gram-negative bacteria, transport of siderophores into the periplasm is mediated by TonB-dependent receptors. A complex of three membrane-spanning proteins TonB, ExbB and ExbD couples the chemiosmotic potential of the cytoplasmic membrane with siderophore uptake across the outer membrane. The crystallographic structures of two TonB-dependent receptors (FhuA and FepA) have recently been determined. These outer membrane transporters show a novel fold consisting of two domains. A 22-stranded antiparallel β-barrel traverses the outer membrane and adjacent β-strands are connected by extracellular loops and periplasmic turns. Located inside the β-barrel is the plug domain, composed primarily of a mixed four-stranded β-sheet and a series of interspersed α-helices. Siderophore binding induces distinct local and allosteric transitions that establish the structural basis of signal transduction across the outer membrane and suggest a transport mechanism.
KW - Outer membrane protein
KW - Siderophore
KW - Signal transduction
KW - TonB-dependent receptor
KW - Transporter
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U2 - 10.1016/S0005-2736(02)00578-3
DO - 10.1016/S0005-2736(02)00578-3
M3 - Review article
C2 - 12409204
AN - SCOPUS:0037064287
SN - 0005-2736
VL - 1565
SP - 318
EP - 332
JO - Biochimica et Biophysica Acta - Biomembranes
JF - Biochimica et Biophysica Acta - Biomembranes
IS - 2
ER -