De novo design of a transmembrane Zn²⁺-transporting four-helix bundle

Science. 2014 Dec 19;346(6216):1520-4. doi: 10.1126/science.1261172.


The design of functional membrane proteins from first principles represents a grand challenge in chemistry and structural biology. Here, we report the design of a membrane-spanning, four-helical bundle that transports first-row transition metal ions Zn(2+) and Co(2+), but not Ca(2+), across membranes. The conduction path was designed to contain two di-metal binding sites that bind with negative cooperativity. X-ray crystallography and solid-state and solution nuclear magnetic resonance indicate that the overall helical bundle is formed from two tightly interacting pairs of helices, which form individual domains that interact weakly along a more dynamic interface. Vesicle flux experiments show that as Zn(2+) ions diffuse down their concentration gradients, protons are antiported. These experiments illustrate the feasibility of designing membrane proteins with predefined structural and dynamic properties.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Carrier Proteins / chemistry*
  • Crystallography, X-Ray
  • Ion Transport
  • Lipid Bilayers
  • Membrane Proteins / chemistry*
  • Micelles
  • Molecular Dynamics Simulation
  • Protein Engineering*
  • Protein Structure, Secondary
  • Zinc / chemistry*


  • Carrier Proteins
  • Lipid Bilayers
  • Membrane Proteins
  • Micelles
  • zinc-binding protein
  • Zinc

Associated data

  • PDB/2MUZ
  • PDB/4P6J
  • PDB/4P6K
  • PDB/4P6L