  Motivation: Identification of flexible regions of protein structures is
important for understanding of their biological functions. Recently, we have
developed a fast approach for predicting protein structure fluctuations from a
single protein model: the CABS-flex. CABS-flex was shown to be an efficient
alternative to conventional all-atom molecular dynamics (MD). In this work, we
evaluate CABS-flex and MD predictions by comparison with protein structural
variations within NMR ensembles.
  Results: Based on a benchmark set of 140 proteins, we show that the relative
fluctuations of protein residues obtained from CABS-flex are well correlated to
those of NMR ensembles. On average, this correlation is stronger than that
between MD and NMR ensembles. In conclusion, CABS-flex is useful and
complementary to MD in predicting of protein regions that undergo
conformational changes and the extent of such changes.
