<p>Linker 2 is positioned between RBD2 and RBD3. Numbers refer to amino acid residue positions in the <i>S</i>. <i>cerevisiae</i> Mrd1p. Linker definition and consensus sequence as previously described [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0175506#pone.0175506.ref010" target="_blank">10</a>]. The most conserved part of Linker 2, between amino acid residues 439 and 524, contains four predicted α-helical regions (green boxes) and one β-strand (purple box). The <i>S</i>. <i>cerevisiae</i> Linker 2 amino acid sequence shared by homologues in other species is shown in bold. The conserved WN and AVK/R clusters are underlined. Single amino acid residue substitutions (W458A, K480E and K494E) are indicated together with three extensive mutations (Swap 1, Swap 2, Scrambled). In WNsubst and AVKsubst, the substitutions are shown in red and their locations are pointed out above the schematic representation of secondary structure predictions. In two additional mutants, 85 amino acid residues (curved line) were inserted, either between RBD2 and Linker 2 (5′-ins) or between Linker 2 and RBD3 (3′-ins).</p
