Comparison of an Atomic Model and Its Cryo-EM Image at the Central Axis of a Helix.
Cryo-electron microscopy (cryo-EM) is an important biophysical technique that produces three-dimensional (3D) density maps at different resolutions. Because more and more models are being produced from cryo-EM density maps, validation of the models is becoming important. We propose a method for measuring local agreement between a model and the density map using the central axis of the helix. This method was tested using 19 helices from cryo-EM density maps between 5.5 Å and 7.2 Å resolution and 94 helices from simulated density maps. This method distinguished most of the well-fitting helices, although challenges exist for shorter helices.
Department of Computer Science, Old Dominion University, Norfolk, VA, 23529.
Jing
J
He
Department of Computer Science, Old Dominion University, Norfolk, VA, 23529.
Stephanie
S
Zeil
Department of Computer Science, Old Dominion University, Norfolk, VA, 23529.
Hussam
H
Hallak
Department of Computer Science, Old Dominion University, Norfolk, VA, 23529.
Kele
K
McKaig
Department of Mechanical & Aerospace Engineering, Old Dominion University, Norfolk, VA, 23529.
Julio
J
Kovacs
Department of Mechanical & Aerospace Engineering, Old Dominion University, Norfolk, VA, 23529.
Willy
W
Wriggers
Validation; cryo-electron microscopy; fitting; image; protein structure; secondary structure