Fig. 3.

GroEL test case. (a) Spherical average of the power of the signal (τ_l², in black) and the annular average of the power of the noise in one of the micrographs (σ_ij², in red) as estimated by MAP refinement. (b) Resolution estimates for the MAP (red) and XMIPP (green) refinements. Broken lines indicate resolution estimates as reported by the refinement program. The broken red line indicates the SSNR^MAP values for the MAP refinement; the broken green line indicates the FSC values as estimated inside XMIPP by splitting the entire data set into two random halves at the final refinement iteration. Continuous lines indicate FSC values between the reconstructions and the crystal structure (see also Experimental Procedures). (c) Guinier plots for the atomic model (black) and the sharpened reconstructions from the MAP (red) and XMIPP (green) refinements. Vertical dotted lines indicate the resolution range that was used to estimate the B-factor for sharpening the experimental reconstruction, using the atomic model as a reference. (d) Density maps for the atomic model at 8 Å resolution (top) and the sharpened reconstruction from the MAP (middle) and XMIPP (bottom) refinements.