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| | <StructureSection load='5aex' size='340' side='right'caption='[[5aex]], [[Resolution|resolution]] 3.20Å' scene=''> | | <StructureSection load='5aex' size='340' side='right'caption='[[5aex]], [[Resolution|resolution]] 3.20Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[5aex]] is a 9 chain structure with sequence from [http://en.wikipedia.org/wiki/Atcc_18824 Atcc 18824]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5AEX OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5AEX FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[5aex]] is a 9 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5AEX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5AEX FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 3.2Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[5aez|5aez]], [[5af1|5af1]]</td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5aex FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5aex OCA], [http://pdbe.org/5aex PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5aex RCSB], [http://www.ebi.ac.uk/pdbsum/5aex PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5aex ProSAT]</span></td></tr> | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=5aex FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5aex OCA], [https://pdbe.org/5aex PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5aex RCSB], [https://www.ebi.ac.uk/pdbsum/5aex PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5aex ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/MEP2_YEAST MEP2_YEAST]] Transporter for ammonium (both charged and uncharged NH3 and NH4) to use as a nitrogen source. The affinity of MEP2 is about twenty times higher than that of MEP1. MEP3 has the lowest affinity. Under ammonium limitation acts as an ammonium sensor, generating a signal that leads to pseudohyphal growth.<ref>PMID:11069679</ref> <ref>PMID:11486013</ref> <ref>PMID:9234685</ref> <ref>PMID:9482721</ref> | + | [https://www.uniprot.org/uniprot/MEP2_YEAST MEP2_YEAST] Transporter for ammonium (both charged and uncharged NH3 and NH4) to use as a nitrogen source. The affinity of MEP2 is about twenty times higher than that of MEP1. MEP3 has the lowest affinity. Under ammonium limitation acts as an ammonium sensor, generating a signal that leads to pseudohyphal growth.<ref>PMID:11069679</ref> <ref>PMID:11486013</ref> <ref>PMID:9234685</ref> <ref>PMID:9482721</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Atcc 18824]] | |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Berg, B van den]] | + | [[Category: Saccharomyces cerevisiae]] |
| - | [[Category: Chembath, A]] | + | [[Category: Chembath A]] |
| - | [[Category: Rutherford, J C]] | + | [[Category: Rutherford JC]] |
| - | [[Category: Membrane protein]] | + | [[Category: Van den Berg B]] |
| Structural highlights
Function
MEP2_YEAST Transporter for ammonium (both charged and uncharged NH3 and NH4) to use as a nitrogen source. The affinity of MEP2 is about twenty times higher than that of MEP1. MEP3 has the lowest affinity. Under ammonium limitation acts as an ammonium sensor, generating a signal that leads to pseudohyphal growth.[1] [2] [3] [4]
Publication Abstract from PubMed
Mep2 proteins are fungal transceptors that play an important role as ammonium sensors in fungal development. Mep2 activity is tightly regulated by phosphorylation, but how this is achieved at the molecular level is not clear. Here we report X-ray crystal structures of the Mep2 orthologues from Saccharomyces cerevisiae and Candida albicans and show that under nitrogen-sufficient conditions the transporters are not phosphorylated and present in closed, inactive conformations. Relative to the open bacterial ammonium transporters, non-phosphorylated Mep2 exhibits shifts in cytoplasmic loops and the C-terminal region (CTR) to occlude the cytoplasmic exit of the channel and to interact with His2 of the twin-His motif. The phosphorylation site in the CTR is solvent accessible and located in a negatively charged pocket approximately 30 A away from the channel exit. The crystal structure of phosphorylation-mimicking Mep2 variants from C. albicans show large conformational changes in a conserved and functionally important region of the CTR. The results allow us to propose a model for regulation of eukaryotic ammonium transport by phosphorylation.
Structural basis for Mep2 ammonium transceptor activation by phosphorylation.,van den Berg B, Chembath A, Jefferies D, Basle A, Khalid S, Rutherford JC Nat Commun. 2016 Apr 18;7:11337. doi: 10.1038/ncomms11337. PMID:27088325[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Marini AM, Andre B. In vivo N-glycosylation of the mep2 high-affinity ammonium transporter of Saccharomyces cerevisiae reveals an extracytosolic N-terminus. Mol Microbiol. 2000 Nov;38(3):552-64. PMID:11069679
- ↑ Soupene E, Ramirez RM, Kustu S. Evidence that fungal MEP proteins mediate diffusion of the uncharged species NH(3) across the cytoplasmic membrane. Mol Cell Biol. 2001 Sep;21(17):5733-41. PMID:11486013
- ↑ Marini AM, Soussi-Boudekou S, Vissers S, Andre B. A family of ammonium transporters in Saccharomyces cerevisiae. Mol Cell Biol. 1997 Aug;17(8):4282-93. PMID:9234685
- ↑ Lorenz MC, Heitman J. The MEP2 ammonium permease regulates pseudohyphal differentiation in Saccharomyces cerevisiae. EMBO J. 1998 Aug 10;17(5):1236-47. PMID:9482721 doi:http://dx.doi.org/10.1093/emboj/17.5.1236
- ↑ van den Berg B, Chembath A, Jefferies D, Basle A, Khalid S, Rutherford JC. Structural basis for Mep2 ammonium transceptor activation by phosphorylation. Nat Commun. 2016 Apr 18;7:11337. doi: 10.1038/ncomms11337. PMID:27088325 doi:http://dx.doi.org/10.1038/ncomms11337
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