“Fluctuograms” Reveal the Intermittent Intra-Protein Communication in Subtilisin Carlsberg and Correlate Mechanical Coupling with Co-Evolution
Figure 4
Sequence correlation in subtilisin.
(a) The residues of subtilisin exhibit high correlation in our multiple sequence alignment determined by a statistical coupling analysis (SCA). Residues with high correlation in sequence variation are divided into three sectors, blue, red, and green according to the eigenvectors of the correlation matrix of sequence conservation [38]. Several residues that are not covered by the selection from the Ca2+-bound fluctuogram are highlighted. (b) The residues that satisfy either of the three criteria discussed in the text from the Ca2+-bound fluctuogram and cover the co-evolved residues shown in (a); color codes are the same as in (a). The parameters of the selection criteria are: = 10,
= 2.5,
= 11,
= 8.0, and
= 0.8. (c) The residues selected from the Ca2+-bound fluctuogram based on the parameters listed in (b). Lime: residues that cover the co-evolved residues from SCA. Brown: the co-evolved residues from SCA that are not covered by the residues selected from the Ca2+-bound fluctuogram. Pink: residues selected from the Ca2+-bound fluctuogram but do not cover any of the co-evolved residues. (d) The residues selected from the Ca2+-bound fluctuogram based on the parameters listed in (b). Blue: residues selected by Criterion-A. Red: residues selected from Criterion-B. Green: residues selected from Criterion-C. See text for the definitions of each criterion.