Fig. 8

Fourier ring correlation (FRC) between the class averages and the particle-picking template of the HIV-1 Env trimer. Panels A-D show the results using the class averages of the simulated data of the HA trimer, with SNR = 0.005 (a), 0.002 (b), 0.001 (c) and 0.0005 (d), corresponding to the results shown in Fig. 5c, f, i and l and Fig. 6c, f, i and l. e shows the results using the pure ice noise data in the absence of any proteins, as demonstrated in Fig. 2f and g. f shows the results obtained with real-world cryo-EM data of the 173-kDa glucose isomerase complex, corresponding to Fig. 7e and f. The solid and dashed curves were computed from the class averages from MLE optimization using the unaligned averages and a Gaussian circle as starting reference, respectively. The color indicates the iteration of MLE optimization at which the class average was computed. For each case, the FRC analysis is shown for a single class average. The results were similar for other class averages in each case