The Amt/MEP/Rh family: structure of AmtB and the mechanism of ammonia gas conduction.

The atomic structures of the first members of the Amt/MEP/Rh family show that they are 11-crossing membrane proteins that form trimers in the membrane. Each monomer supports a hydrophobic channel that conducts NH(3) but not any water or ions. The reprotonation of NH(3) on the receiving side raises the pH on that side in the absence of metabolism of NH(3), and there is no transfer of protons through the protein.

[1]  Jan-Fang Cheng,et al.  Characterization of Human RhCG and Mouse Rhcg as Novel Nonerythroid Rh Glycoprotein Homologues Predominantly Expressed in Kidney and Testis* , 2000, The Journal of Biological Chemistry.

[2]  Christopher Miller,et al.  Secondary active transport mediated by a prokaryotic homologue of ClC Cl- channels , 2004, Nature.

[3]  Robert M. Stroud,et al.  Mechanism of Ammonia Transport by Amt/MEP/Rh: Structure of AmtB at 1.35 Å , 2004, Science.

[4]  L. Miercke,et al.  Water and glycerol permeation through the glycerol channel GlpF and the aquaporin family. , 2004, Journal of synchrotron radiation.

[5]  M. Knepper.  NH4+ transport in the kidney. , 1991, Kidney international. Supplement.

[6]  G. Calamita,et al.  Purification and functional characterization of aquaporin‐8 , 2006, Biology of the cell.

[7]  W. Inwood,et al.  Lack of the Rhesus protein Rh1 impairs growth of the green alga Chlamydomonas reinhardtii at high CO2. , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[8]  Bert van den Berg,et al.  X-ray structure of a protein-conducting channel , 2004, Nature.

[9]  Gunnar von Heijne,et al.  Experimentally constrained topology models for 51,208 bacterial inner membrane proteins. , 2005, Journal of molecular biology.

[10]  Peter Agre,et al.  Structural basis for conductance by the archaeal aquaporin AqpM at 1.68 A. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[11]  Y. Mo,et al.  Molecular dynamics simulations on the Escherichia coli ammonia channel protein AmtB: mechanism of ammonia/ammonium transport. , 2006, Journal of the American Chemical Society.

[12]  P. Gane,et al.  Human Rhesus-associated glycoprotein mediates facilitated transport of NH(3) into red blood cells. , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[13]  M. J. Conroy,et al.  Modelling the human rhesus proteins: implications for structure and function , 2005, British journal of haematology.

[14]  R. Chambrey,et al.  RhBG and RhCG, the putative ammonia transporters, are expressed in the same cells in the distal nephron. , 2003, Journal of the American Society of Nephrology.

[15]  Robert M Stroud,et al.  The channel architecture of aquaporin 0 at a 2.2-A resolution. , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[16]  W. Frommer,et al.  The molecular physiology of ammonium uptake and retrieval. , 2000, Current opinion in plant biology.

[17]  Mike Merrick,et al.  In Vitro Analysis of the Escherichia coli AmtB-GlnK Complex Reveals a Stoichiometric Interaction and Sensitivity to ATP and 2-Oxoglutarate* , 2006, Journal of Biological Chemistry.

[18]  W F Boron,et al.  Intracellular pH. , 1981, Physiological reviews.

[19]  C. Hui,et al.  Rh Type B Glycoprotein Is a New Member of the Rh Superfamily and a Putative Ammonia Transporter in Mammals* , 2001, The Journal of Biological Chemistry.

[20]  B. André,et al.  The human Rhesus-associated RhAG protein and a kidney homologue promote ammonium transport in yeast , 2000, Nature Genetics.

[21]  Thomas Zeuthen,et al.  Aquaporin homologues in plants and mammals transport ammonia , 2004, FEBS letters.

[22]  A. Burkovski,et al.  Multiplicity of ammonium uptake systems in Corynebacterium glutamicum: role of Amt and AmtB. , 2001, Microbiology.

[23]  S. Kustu,et al.  Ammonium/methylammonium transport (Amt) proteins facilitate diffusion of NH3 bidirectionally , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[24]  M. Hemker,et al.  The Rh complex exports ammonium from human red blood cells , 2003, British journal of haematology.

[25]  M. Tanner,et al.  Studies on the glycoprotein associated with Rh (rhesus) blood group antigen expression in the human red blood cell membrane. , 1994, The Journal of biological chemistry.

[26]  Bong-Gyoon Han,et al.  Structural basis of water-specific transport through the AQP1 water channel , 2001, Nature.

[27]  G. Thomas,et al.  Purification of the Escherichia coli ammonium transporter AmtB reveals a trimeric stoichiometry. , 2002, The Biochemical journal.

[28]  R. Dutzler,et al.  X-ray structure of a ClC chloride channel at 3.0 Å reveals the molecular basis of anion selectivity , 2002, Nature.

[29]  I. Paulsen,et al.  Major Facilitator Superfamily , 1998, Microbiology and Molecular Biology Reviews.

[30]  M. J. Conroy,et al.  The Escherichia coli AmtB protein as a model system for understanding ammonium transport by Amt and Rh proteins. , 2006, Transfusion clinique et biologique : journal de la Societe francaise de transfusion sanguine.

[31]  Gunnar von Heijne,et al.  Identification and evolution of dual-topology membrane proteins , 2006, Nature Structural &Molecular Biology.

[32]  G. Thomas,et al.  Membrane topology of the Mep/Amt family of ammonium transporters , 2000, Molecular microbiology.

[33]  B. André,et al.  Structural involvement in substrate recognition of an essential aspartate residue conserved in Mep/Amt and Rh-type ammonium transporters , 2006, Current Genetics.

[34]  Robert M Stroud,et al.  Architecture and Selectivity in Aquaporins: 2.5 Å X-Ray Structure of Aquaporin Z , 2003, PLoS biology.

[35]  N. Avent.  A new chapter in Rh research: Rh proteins are ammonium transporters. , 2001, Trends in molecular medicine.

[36]  J. Verlander,et al.  Renal and hepatic expression of the ammonium transporter proteins, Rh B Glycoprotein and Rh C Glycoprotein. , 2003, Acta physiologica Scandinavica.

[37]  S. Howitt,et al.  Structure, function and regulation of ammonium transporters in plants. , 2000, Biochimica et biophysica acta.

[38]  Søren Brunak,et al.  A Neural Network Method for Identification of Prokaryotic and Eukaryotic Signal Peptides and Prediction of their Cleavage Sites , 1997, Int. J. Neural Syst..

[39]  I. H. Segel,et al.  Characterization of an ammonium transport system in filamentous fungi with methylammonium-14C as the substrate. , 1970, The Journal of biological chemistry.

[40]  M. Tanner,et al.  Topology and organization of human Rh (rhesus) blood group-related polypeptides. , 1994, The Journal of biological chemistry.

[41]  M. Zeidel,et al.  Apical membrane of the gastric parietal cell: water, proton, and nonelectrolyte permeabilities. , 1993, Biochemistry.

[42]  A. Engel,et al.  Electron and atomic force microscopy of the trimeric ammonium transporter AmtB , 2004, EMBO reports.

[43]  Mike Merrick,et al.  In vivo functional characterization of the Escherichia coli ammonium channel AmtB: evidence for metabolic coupling of AmtB to glutamine synthetase. , 2005, The Biochemical journal.

[44]  D. Hunt,et al.  Gas Channels for NH3: Proteins from Hyperthermophiles Complement an Escherichia coli Mutant , 2002, Journal of bacteriology.

[45]  Roderick MacKinnon,et al.  Energetic optimization of ion conduction rate by the K+ selectivity filter , 2001, Nature.

[46]  W. Frommer,et al.  Urea Transport by Nitrogen-Regulated Tonoplast Intrinsic Proteins in Arabidopsis1 , 2003, Plant Physiology.

[47]  W. Frommer,et al.  Preferential expression of an ammonium transporter and of two putative nitrate transporters in root hairs of tomato. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[48]  Roderick MacKinnon,et al.  Gating the Selectivity Filter in ClC Chloride Channels , 2003, Science.

[49]  B. André,et al.  The Rh (rhesus) blood group polypeptides are related to NH4+ transporters. , 1997, Trends in biochemical sciences.

[50]  M. Knepper,et al.  Ammonium transport in the kidney. , 1989, Physiological reviews.

[51]  R. Ficner,et al.  Crystal structure of the archaeal ammonium transporter Amt-1 from Archaeoglobus fulgidus. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[52]  D. Fu,et al.  Structure of a glycerol-conducting channel and the basis for its selectivity. , 2000, Science.

[53]  N. Avent.  Molecular Biology of the Rh Blood Group System , 2001, Journal of pediatric hematology/oncology.

[54]  M H Saier,et al.  Phylogenetic characterization of novel transport protein families revealed by genome analyses. , 1999, Biochimica et biophysica acta.

[55]  Youxing Jiang,et al.  The open pore conformation of potassium channels , 2002, Nature.

[56]  Da-Neng Wang,et al.  Structure and Mechanism of the Glycerol-3-Phosphate Transporter from Escherichia coli , 2003, Science.

[57]  Zhi Liu,et al.  The Mouse Rhl1 and Rhag Genes: Sequence, Organization, Expression, and Chromosomal Mapping , 1999, Biochemical Genetics.

[58]  J. Foskett,et al.  Identification of the Erythrocyte Rh Blood Group Glycoprotein as a Mammalian Ammonium Transporter* , 2002, The Journal of Biological Chemistry.

[59]  Thomas P. Jahn,et al.  NH3 and NH4+ permeability in aquaporin-expressing Xenopus oocytes , 2005, Pflügers Archiv.

[60]  S. Kustu,et al.  Ammonia acquisition in enteric bacteria: physiological role of the ammonium/methylammonium transport B (AmtB) protein. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[61]  W. Frommer,et al.  Three Functional Transporters for Constitutive, Diurnally Regulated, and Starvation-Induced Uptake of Ammonium into Arabidopsis Roots , 1999, Plant Cell.

[62]  S. Iwata,et al.  Structure and Mechanism of the Lactose Permease of Escherichia coli , 2003, Science.

[63]  Eric Gouaux,et al.  Crystal structure of a bacterial homologue of Na+/Cl--dependent neurotransmitter transporters , 2005, Nature.

[64]  E. M. Barnes,et al.  A filtration method for measuring cellular uptake of [14C]methylamine and other highly permeant solutes. , 1983, Analytical biochemistry.

[65]  J. H. Park,et al.  Phylogenetic Characterization of the MIP Family of Transmembrane Channel Proteins , 1996, The Journal of Membrane Biology.

[66]  M. Merrick,et al.  The glnKamtB operon. A conserved gene pair in prokaryotes. , 2000, Trends in genetics : TIG.

[67]  J. Cartron,et al.  Rh proteins: key structural and functional components of the red cell membrane. , 2006, Blood reviews.

[68]  M. Merrick,et al.  Complex formation between AmtB and GlnK: an ancestral role in prokaryotic nitrogen control. , 2005, Biochemical Society transactions.

[69]  W. Inwood,et al.  Biological gas channels for NH3 and CO2: evidence that Rh (Rhesus) proteins are CO2 channels. , 2006, Transfusion clinique et biologique : journal de la Societe francaise de transfusion sanguine.

[70]  J. Jauniaux,et al.  Identification of a high affinity NH4+ transporter from plants. , 1994, The EMBO journal.

[71]  Simon Bernèche,et al.  The mechanism of ammonia transport based on the crystal structure of AmtB of Escherichia coli. , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[72]  L. Hamm,et al.  Non-erythroid Rh glycoproteins: a putative new family of mammalian ammonium transporters , 2004, Pflügers Archiv.

[73]  J. Broach,et al.  Mutant strains (nit) of Salmonella typhimurium with a pleiotropic defect in nitrogen metabolism , 1976, Journal of bacteriology.