Figure 1
Figure 1. (A) Partial FoxB model obtained by experimental
phasing before the CASP14 model became available. At this point the
model could not be further improved and the project was stuck for a
year. (B) Experimental phases with partial FoxB model (map shown at 1.2σ
level).
At that point we were stuck with experimental phasing and submitted the
FoxB sequence to CASP14. The model provided by AlphaFold2
(T1058TS427_3) resulted in a clear molecular replacement (MR) solution
(TFZ: 18.9 / LLG: 324). We have also succeeded in finding a suitable
crystal which diffracted to better than 3.5 Å, the crystal belonged to
the P21212 space group and contained 2
molecules of FoxB in the asymmetric unit. The final resolution of the
diffraction dataset after starANISO processing was 3.1 Å. Subsequent
MR-SAD and several rounds of building/refinement using COOT19 and REFMAC20 further improved the
model and resulted in a good electron density map for the entire
protein. Anomalous difference maps were also used to validate the model
(Fig. 2).