Protein structures are highly dynamic macromolecules. Molecular dynamics (MDs) simulations were performed on 169 representative protein domains. Classical secondary structures were explored. Concerning the helical structures, only 76.4% of the residues associated to α-helices retain the conformation; this tendency dropped to 40% for 310- and for π-helices [1]. The rigidity of β-sheet was confirmed, but showed its capacity to transform into turns. Finally, turns converted easily to helical structures while bends prefer the extended conformations. Protein Blocks structural alphabet [2] showed that the majority of PBs remains with high frequency in original conformation. Few PBs have a higher tendency to be more flexible. The intriguing fact was that the change from a PB to another one did not correspond to a simple geometrical evolution. It was more frequent to go to an unexpected PB than an expected one [3]. Disorder protein ensembles were analysed with PBs allowing to quantify the continuum from rigidity to flexibility and finally disorder [4,5]. These results have been compared to different types of prediction [6,7].

1. Narwani, T.J.; Craveur, P.; Shinada, N.K.; Santuz, H.; Rebehmed, J.; Etchebest, C.; de Brevern, A.G. Dynamics and deformability of α-, 310- and π-helices. Archives of Biological Sciences 2018, 70, 21-31.
2. de Brevern, A.G.; Etchebest, C.; Hazout, S. Bayesian probabilistic approach for predicting backbone structures in terms of protein blocks. Proteins 2000, 41, 271-287.
3. Narwani, T.J.; Craveur, P.; Shinada, N.K.; Floch, A.; Santuz, H.; Vattekatte, A.M.; Srinivasan, N.;
Rebehmed, J.; Gelly, J.C.; Etchebest, C., et al. Discrete analyses of protein dynamics. J Biomol Struct Dyn 2019, 1-15.
4. Melarkode Vattekatte, A.; Narwani, T.J.; Floch, A.; Maljkovic, M.; Bisoo, S.; Shinada, N.K.; Kranjc, A.;
Gelly, J.C.; Srinivasan, N.; Mitic, N., et al. Data set of intrinsically disordered proteins analysed at a local protein conformation level. Data Brief 2020, 29, 105383.
5. Melarkode Vattekatte, A.; Narwani, T.J.; Floch, A.; Maljkovic, M.; Bisoo, S.; Shinada, N.K.; Kranjc, A.;
Gelly, J.C.; Srinivasan, N.; Mitic, N., et al. A structural entropy index to analyse local conformations in intrinsically disordered proteins. J Struct Biol 2020, 210, 107464.
6. de Brevern, A.G. Analysis of protein disorder predictions in the light of a protein structural alphabet. Biomolecules 2020, 10.
7. de Brevern, A.G. Impact of protein dynamics on secondary structure prediction. Biochimie 2020, 179, 14-22.