Single particle refinement in electron crystallography: a pilot study.
Electron crystallography can be used to determine the structures of membrane proteins at near-atomic resolution in some cases. However, most electron crystallography projects remain at a resolution around 10A. This might be partly due to lack of flatness of many two-dimensional crystals. We have investigated this problem and suggest single particle processing of locally averaged unit cells to improve the quality and possibly the resolution of three-dimensional maps. Applying this method to the secondary transporter melibiose permease we have calculated a three-dimensional map that is clearer and easier to interpret than the map derived using purely electron-crystallographic methods.
Koeck
Philip J B
PJ
Royal Institute of Technology, School of Technology and Health, Sweden. Philip.Koeck@csb.ki.se
Purhonen
Pasi
P
Alvang
Ronny
R
Grundberg
Björn
B
Hebert
Hans
H
D003198:Computer Simulation; D003460:Crystallization; D003461:Crystallography / Q000379:methods*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000648:ultrastructure; D005583:Fourier Analysis; D021621:Imaging, Three-Dimensional / Q000379:methods*; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D008958:Models, Molecular; D010865:Pilot Projects; D011487:Protein Conformation; D027981:Symporters / Q000737:chemistry / Q000648:ultrastructure
D029968:Escherichia coli Proteins; D027981:Symporters; C021548:melibiose permease