DCA Web Server
DCA calculation from RNA sequence or Multiple alignment sequence alignment
Direct Coupling Analysis (DCA) is a statistical inference framework used to infer direct co-evolutionary couplings among residue pairs in multiple sequence alignments, which aims at disentangling direct from indirect correlations. The common idea of these methods is to use statistical modeling to quantify the strength of the direct relationship between two positions of a biological sequence, excluding effects from other positions. This contrasts usual measures of correlation, which can be large even if there is no direct relationship between the positions (hence the name direct coupling analysis). Such a direct relationship can for example be the evolutionary pressure for two positions to maintain mutual compatibility in the biomolecular structure of the sequence, leading to molecular coevolution between the two positions.