Rational design of true monomeric and bright photoactivatable fluorescent proteins

Nat Methods. 2012 May 13;9(7):727-9. doi: 10.1038/nmeth.2021.


Monomeric (m)Eos2 is an engineered photoactivatable fluorescent protein widely used for super-resolution microscopy. We show that mEos2 forms oligomers at high concentrations and forms aggregates when labeling membrane proteins, limiting its application as a fusion partner. We solved the crystal structure of tetrameric mEos2 and rationally designed improved versions, mEos3.1 and mEos3.2, that are truly monomeric, are brighter, mature faster and exhibit higher photon budget and label density.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • COS Cells
  • Chlorocebus aethiops
  • Chromatography, Gel
  • Green Fluorescent Proteins* / chemistry
  • Green Fluorescent Proteins* / genetics
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Luminescent Proteins* / chemistry
  • Luminescent Proteins* / genetics
  • Microscopy, Fluorescence / methods*
  • Models, Molecular
  • Photochemical Processes
  • Plasmids
  • Protein Conformation
  • Protein Engineering / methods*
  • Transfection


  • Luminescent Proteins
  • red fluorescent protein
  • Green Fluorescent Proteins