2X79

Inward facing conformation of Mhp1

• PDB DOI:  https://doi.org/10.2210/pdb2X79/pdb

• Classification: TRANSPORT PROTEIN
• Organism(s): Microbacterium liquefaciens
• Expression System: Escherichia coli
• Mutation(s): No 
• Membrane Protein: Yes  OPMPDBTMMemProtMDmpstruc


• Deposited: 2010-02-25 Released: 2010-05-05 
• Deposition Author(s): Shimamura, T., Weyand, S., Beckstein, O., Rutherford, N.G., Hadden, J.M., Sharples, D., Sansom, M.S.P., Iwata, S., Henderson, P.J.F., Cameron, A.D.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 3.80 Å
• R-Value Free: 0.313 
• R-Value Work: 0.273 
• R-Value Observed: 0.277 

Literature

Molecular Basis of Alternating Access Membrane Transport by the Sodium-Hydantoin Transporter Mhp1.

Shimamura, T., Weyand, S., Beckstein, O., Rutherford, N.G., Hadden, J.M., Sharples, D., Sansom, M.S.P., Iwata, S., Henderson, P.J.F., Cameron, A.D.

(2010) Science 328: 470

• PubMed: 20413494 
• DOI: https://doi.org/10.1126/science.1186303
• Primary Citation of Related Structures:  
  2X79


• PubMed Abstract: 
  

The structure of the sodium-benzylhydantoin transport protein Mhp1 from Microbacterium liquefaciens comprises a five-helix inverted repeat, which is widespread among secondary transporters. Here, we report the crystal structure of an inward-facing conformation of Mhp1 at 3.8 angstroms resolution, complementing its previously described structures in outward-facing and occluded states. From analyses of the three structures and molecular dynamics simulations, we propose a mechanism for the transport cycle in Mhp1. Switching from the outward- to the inward-facing state, to effect the inward release of sodium and benzylhydantoin, is primarily achieved by a rigid body movement of transmembrane helices 3, 4, 8, and 9 relative to the rest of the protein. This forms the basis of an alternating access mechanism applicable to many transporters of this emerging superfamily.

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Organizational Affiliation: 

Division of Molecular Biosciences, Membrane Protein Crystallography Group, Imperial College, London SW7 2AZ, UK.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 55.56 kDa 
• Atom Count: 3,585 
• Modelled Residue Count: 465 
• Deposited Residue Count: 501 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
HYDANTOIN TRANSPORT PROTEIN	A	501	Microbacterium liquefaciens	Mutation(s): 0  Gene Names: hyuP Membrane Entity: Yes
UniProt
Find proteins for D6R8X8 (Microbacterium liquefaciens) Explore D6R8X8  Go to UniProtKB:  D6R8X8

Small Molecules

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
MSE	A	L-PEPTIDE LINKING	C5 H11 N O2 Se		MET

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 3.80 Å
• R-Value Free: 0.313 
• R-Value Work: 0.273 
• R-Value Observed: 0.277 
• Space Group: P 6₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 173.888	α = 90
b = 173.888	β = 90
c = 74.502	γ = 120

Software Package:

Software Name	Purpose
PHENIX	refinement
DENZO	data reduction
SCALEPACK	data scaling
SHARP	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2010-05-05 
Deposition Author(s): Shimamura, T., Weyand, S., Beckstein, O., Rutherford, N.G., Hadden, J.M., Sharples, D., Sansom, M.S.P., Iwata, S., Henderson, P.J.F., Cameron, A.D.

Revision History  

• Version 1.0: 2010-05-05
  Type: Initial release
  
• Version 1.1: 2011-05-08
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance