Model-based particle picking for cryo-electron microscopy.
We describe an algorithm for finding particle images in cryo-EM micrographs. The algorithm starts from a crude 3D map of the target particle, computed from a relatively small number of manually picked images, and then projects the map in many different directions to give synthetic 2D templates. The templates are clustered and averaged and then cross-correlated with the micrographs. A probabilistic model of the imaging process then scores cross-correlation peaks to produce the final picks. We give quantitative results on two quite different target particles: keyhole limpet hemocyanin and p97 AAA ATPase. On these particles our automatic particle picker shows human performance level, as measured by the Fourier shell correlations of 3D reconstructions.
Wong
H Chi
HC
Palo Alto Research Center, 3333 Coyote Hill Rd, Palo Alto, CA 94070, USA. hcwong@parc.com
Chen
Jindong
J
Mouche
Fabrice
F
Rouiller
Isabelle
I
Bern
Marshall
M
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000648:ultrastructure; D000465:Algorithms; D000818:Animals; D020285:Cryoelectron Microscopy / Q000379:methods*; D001330:Electronic Data Processing / Q000379:methods; D005583:Fourier Analysis; D006433:Hemocyanins / Q000737:chemistry / Q000648:ultrastructure; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D016013:Likelihood Functions; D008958:Models, Molecular; D015233:Models, Statistical; D008974:Mollusca; D009687:Nuclear Proteins / Q000737:chemistry / Q000648:ultrastructure; D010316:Particle Size; D010363:Pattern Recognition, Automated; D011487:Protein Conformation; D012985:Software Design
D009687:Nuclear Proteins; D006433:Hemocyanins; D000251:Adenosine Triphosphatases; C404942:p97 ATPase; C032808:keyhole-limpet hemocyanin