Ammonia transporter

Ammonia transporter
Human Rhesus C Glycoprotein. PDB 3hd6[1]
Identifiers
SymbolAmtB
PfamPF00909
InterProIPR001905
TCDB1.A.11
OPM superfamily13
OPM protein2ns1
Available protein structures:
Pfam  structures / ECOD  
PDBRCSB PDB; PDBe; PDBj
PDBsumstructure summary

Ammonia transporters (TC# 1.A.11) are structurally related membrane transport proteins called Amt proteins (ammonia transporters) in bacteria and plants, methylammonium/ammonium permeases (MEPs) in yeast, or Rhesus (Rh) proteins in chordates. In humans, the RhAG, RhBG, and RhCG Rhesus proteins constitute solute carrier family 42[2] whilst RhD and RhCE form the Rh blood group system. The three-dimensional structure of the ammonia transport protein AmtB from Escherichia coli has been determined by x-ray crystallography[3][4] revealing a hydrophobic ammonia channel.[5] The human RhCG ammonia transporter was found to have a similar ammonia-conducting channel structure.[1] It was proposed[citation needed] that the erythrocyte Rh complex is a heterotrimer of RhAG, RhD, and RhCE subunits in which RhD and RhCE might play roles in anchoring the ammonia-conducting RhAG subunit to the cytoskeleton. Based on reconstitution experiments, purified RhCG subunits alone can function to transport ammonia.[6] RhCG is required for normal acid excretion by the mouse kidney[7] and epididymis.[8]

  1. ^ a b Gruswitz, F.; Chaudhary, S.; Ho, J. D.; Schlessinger, A.; Pezeshki, B.; Ho, C. -M.; Sali, A.; Westhoff, C. M.; Stroud, R. M. (2010). "Function of human Rh based on structure of RhCG at 2.1 A". Proceedings of the National Academy of Sciences. 107 (21): 9638–9643. doi:10.1073/pnas.1003587107. PMC 2906887. PMID 20457942.
  2. ^ Nakhoul NL, Hamm LL (Feb 2004). "Non-erythroid Rh glycoproteins: a putative new family of mammalian ammonium transporters". Pflügers Archiv. 447 (5): 807–12. doi:10.1007/s00424-003-1142-8. PMID 12920597. S2CID 24601165.
  3. ^ 1xqe; Khademi S, O'Connell J, Remis J, Robles-Colmenares Y, Miercke LJ, Stroud RM (Sep 2004). "Mechanism of ammonia transport by Amt/MEP/Rh: structure of AmtB at 1.35 A". Science. 305 (5690): 1587–94. CiteSeerX 10.1.1.133.6480. doi:10.1126/science.1101952. PMID 15361618. S2CID 11436509.
  4. ^ 2u7c; Zheng L, Kostrewa D, Bernèche S, Winkler FK, Li XD (Dec 2004). "The mechanism of ammonia transport based on the crystal structure of AmtB of Escherichia coli". Proceedings of the National Academy of Sciences of the United States of America. 101 (49): 17090–5. Bibcode:2004PNAS..10117090Z. doi:10.1073/pnas.0406475101. PMC 535379. PMID 15563598.
  5. ^ Khademi S, Stroud RM (Dec 2006). "The Amt/MEP/Rh family: structure of AmtB and the mechanism of ammonia gas conduction". Physiology. 21 (6): 419–29. doi:10.1152/physiol.00051.2005. PMID 17119155.
  6. ^ Mouro-Chanteloup I, Cochet S, Chami M, Genetet S, Zidi-Yahiaoui N, Engel A, Colin Y, Bertrand O, Ripoche P (2010). Fatouros D (ed.). "Functional reconstitution into liposomes of purified human RhCG ammonia channel". PLOS ONE. 5 (1): e8921. Bibcode:2010PLoSO...5.8921M. doi:10.1371/journal.pone.0008921. PMC 2812482. PMID 20126667.
  7. ^ Wagner CA, Devuyst O, Belge H, Bourgeois S, Houillier P (Jan 2011). "The rhesus protein RhCG: a new perspective in ammonium transport and distal urinary acidification" (PDF). Kidney International. 79 (2): 154–61. doi:10.1038/ki.2010.386. PMID 20927037.
  8. ^ Biver S, Belge H, Bourgeois S, Van Vooren P, Nowik M, Scohy S, Houillier P, Szpirer J, Szpirer C, Wagner CA, Devuyst O, Marini AM (Nov 2008). "A role for Rhesus factor Rhcg in renal ammonium excretion and male fertility". Nature. 456 (7220): 339–43. Bibcode:2008Natur.456..339B. doi:10.1038/nature07518. PMID 19020613. S2CID 205215412.