Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction | Predict Membrane 

Global Symmetry: Cyclic - C3  (3D View)
Global Stoichiometry: Homo 3-mer - A3 

Biological assembly 1 generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 54.32 kDa 
• Atom Count: 3886 
• Modelled Residue Count: 455 
• Deposited Residue Count: 486 
• Unique protein chains: 1

5AEZ

Crystal structure of Candida albicans Mep2

• DOI: 10.2210/pdb5AEZ/pdb

• Classification: MEMBRANE PROTEIN
• Organism(s): Candida albicans
• Expression System: Saccharomyces cerevisiae
• Mutation(s): No 
• Membrane Protein: Yes  PDBTMMemProtMDmpstruc


• Deposited: 2015-01-12 Released: 2016-01-20 
• Deposition Author(s): Rutherford, J.C., Chembath, A., van den Berg, B.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.47 Å
• R-Value Free: 0.150 
• R-Value Work: 0.137 
• R-Value Observed: 0.138 

Literature

Structural Basis for Mep2 Ammonium Transceptor Activation by Phosphorylation.

Van Den Berg, B., Chembath, A., Jefferies, D., Basle, A., Khalid, S., Rutherford, J.

(2016) Nat Commun 7: 11337

• PubMed: 27088325 
• DOI: 10.1038/ncomms11337
• Primary Citation of Related Structures:  
  5FUF, 5AEX, 5AF1, 5AEZ, 5AH3, 5AID


• PubMed Abstract: 
  

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 ∼30 Å 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.

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Organizational Affiliation: 

Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
MEP2	A	486	Candida albicans	Mutation(s): 0  Membrane Entity: Yes
UniProt
Find proteins for Q59UP8 (Candida albicans (strain SC5314 / ATCC MYA-2876)) Explore Q59UP8  Go to UniProtKB:  Q59UP8

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
BNG	B [auth A], C [auth A], D [auth A], E [auth A], F [auth A]	nonyl beta-D-glucopyranoside C15 H30 O6 QFAPUKLCALRPLH-UXXRCYHCSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.47 Å
• R-Value Free: 0.150 
• R-Value Work: 0.137 
• R-Value Observed: 0.138 
• Space Group: H 3

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 104.88	α = 90
b = 104.88	β = 90
c = 160.65	γ = 120

Software Package:

Software Name	Purpose
PHENIX	refinement
XDS	data reduction
Aimless	data scaling
PHASER	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2015-01-12 
• Released Date: 2016-01-20 
Deposition Author(s): Rutherford, J.C., Chembath, A., van den Berg, B.

Revision History  

• Version 1.0: 2016-01-20
  Type: Initial release
  
• Version 1.1: 2016-05-04
  Changes: Database references
• Version 1.2: 2016-05-11
  Changes: Database references
• Version 1.3: 2020-07-29
  Type: Remediation
  Reason: Carbohydrate remediation
  Changes: Advisory, Data collection, Derived calculations, Other, Structure summary