Heavy meromyosin from Schistosoma mansoni muscle thick filament by negative stain EM
ELECTRON MICROSCOPY
Sample
Myosin thick filaments from Schistosoma mansoni smooth muscle
Sample Components
Myosin II
Specimen Preparation
Sample Aggregation State
FILAMENT
Staining Type
NEGATIVE
Staining Material
Uranyl Acetate
Staining Details
3D Reconstruction
Reconstruction Method
HELICAL
Number of Particles
9500
Reported Resolution (Å)
23
Resolution Method
FSC 0.5 CUT-OFF
Other Details
For each iteration of reconstruction (30 cycles), filament segment projections were compared with different projections of the reference reconstructio ...
For each iteration of reconstruction (30 cycles), filament segment projections were compared with different projections of the reference reconstruction as follows: seven 2.3 nm axial shifts, 2 degree intervals of rotation about the filament axis up to 90 degrees, and 2 degree intervals of out-of-plane tilting from -10 degrees to +10 degrees. The total number of projections was 7 x 45 x 11 = 3465. For the final 19 cycles of the reconstruction, we used only the best-ordered 420 filament halves (those in which >30% of the segments were found good enough to be used by the reconstruction script in the back-projection in previous cycles). From ~17,000 segments, ~9,500 (56%) were included in the final reconstruction. This final 3D-reconstruction was the average of the last 19 reconstructions between cycles 12 - 30. Its resolution, according to the 0.5 Fourier Shell Correlation (FSC) criterion, was 2.3 nm.
Refinement Type
Symmetry Type
HELICAL
Axial Symmetry
C4
Axial Rise
145
Angular Rotation
30
Map-Model Fitting and Refinement
Id
1 (3DTP, 3DTP, 3DTP, 3DTP, 3DTP, 3DTP)
Refinement Space
REAL
Refinement Protocol
RIGID BODY FIT
Refinement Target
Overall B Value
Fitting Procedure
Details
METHOD--rigid docking REFINEMENT PROTOCOL--RIGID BODY DETAILS--3DTP was fitted
as a rigid body using the Fit in Map tool of UCSF Chimera.
