Overview of the results
To analyze our performance in CASP14 we used several accuracy measures
designed to evaluate various features of multimeric models. For the
overall model evaluation we used QS-score, a distance-based measure of
interface accuracy36. To make qualitative model
accuracy assignments we converted QS-score values to CAPRI-like accuracy
categories37. Four other scores were used to assess
the interface and the overall structure accuracy. Interface Contact
Similarity (ICS or F1-score) and Interface Patch Similarity (IPS or
Jaccard coefficient) were used to assess contact and interface patch
prediction, respectively13. Oligomeric lDDT and
TM-score were used to assess overall structure accuracy. LDDT is an
all-atom superposition-free score38, whereas TM-score
is based on the rigid body superposition of Cα atoms39,
40. In addition to the above scores reported by the Prediction Center,
we also used CAD-score31, 32 to evaluate the accuracy
of both structure and interface accuracy.
The summary of our modeling results based on QS-score is presented in
Table 1, whereas the detailed accuracy evaluation of our best models is
provided in Supplementary Table S1. As can be seen in Table 1, for 11
targets we identified multimeric templates and used comparative
modeling, producing medium or high-accuracy models for 8 of them. In the
absence of reliable target-template sequence-structure alignments, we
applied template-based docking using TM-align. This approach resulted in
models of medium accuracy for 2 targets. Hybrid approaches utilizing
both comparative modeling and docking steps were used for 9 targets with
relative success. The results of free docking were ranging from
completely incorrect to medium accuracy models. The custom modeling
procedure that we used for coiled-coils did not produce any reliable
models.