(
A) Phylogenetic tree built from the J-domains of class A J-proteins. Color-coding separates different phylogenetic groups. Grey area highlights the separation of eukaryotes (fungi, viridiplantae and other eukaryotes) from prokaryotes (proteobacteria, firmicutes and other bacteria) and Archaea. (
B) As in (
A), built from the CTDs of class B J-proteins. Pink lines delimit organellar sequences of eukaryotic organisms. (
C) Structural view of PDA predicted most discriminating positions (red) plotted on the JD of DNAJA2 (green, six positions) and the CTD of DNAJB1 (blue, nine positions). DCA derived coevolving residue pairs depicted on DNAJB1
JD and DNAJA2
CTD (orange). Experimentally determined cross-linking residues between the DNAJA2
JD and the DNAJB1
CTD are indicated in purple (
Nillegoda et al., 2015). Location of the triple charge reversion (E/D→R) mutations that disrupts interclass J-protein complex formation between DNAJB1 and DNAJA2 denoted by (*) (
Nillegoda et al., 2015). The HPD motif of DNAJB1
JD is shown in grey. (
D) Mapping of sequence clustering derived from PDA (see Materials and methods) using the most discriminating positions on to JD and CTD trees of class A and class B J-proteins, respectively. The two identified groups (green and yellow nodes) covered 78% in the case of the clustering done on the JDs and 100% when clustering was done on the CTDs. Unclassified sequences are depicted in white. (
E) Graph showing the distribution of predicted DCA pairs between class B
JDs and class A
CTDs. The threshold for obtaining statistically significant inter-protein coevolving pairs was set at 5% of contact appearance after 300 realizations. DCA-derived coevolving residue pair on DNAJA2
JD and DNAJB1
CTD (orange). Neighboring charged residues are depicted in black. (
F) As in (
E) graph showing the distribution of predicted DCA pairs between class A
JDs and class B
CTDs.