Ligand binding induces an asymmetrical transmembrane signal through a receptor dimer.
Two ligand (aspartate)-binding pockets are formed at the interface between the subunits of the Tar homodimer, a bacterial chemoreceptor. Using mutant heterodimers of a hybrid receptor, Taz1, which consists of the external domain of Tar and the cytoplasmic domain of EnvZ, we disrupted either one or the other of the two ligand-binding pockets. We found that occupation of only one of the ligand-binding pockets was sufficient for induction of a transmembrane signal, and that the subunit responsible for the binding of the amino group of the ligand transduces the signal.
Yang
Y
Y
Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Rutgers, Piscataway 08854.
Park
H
H
Inouye
M
M
D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002628:Chemoreceptor Cells; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D015398:Signal Transduction; D001616:beta-Galactosidase / Q000096:biosynthesis
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D009097:Multienzyme Complexes; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; C057331:Tar protein, E coli; C072091:Taz1 protein, E coli; D011494:Protein Kinases; C057843:envZ protein, E coli; D010749:Phosphoprotein Phosphatases; D001616:beta-Galactosidase