Fig. 4.

Homology 3-D model of RelSt3 core-domain. a Schematic view of the secondary structure of RelSt3 core domain (PF02486). Beta-strands are represented as arrows and helices as cylinders, with lengths proportional to the numbers of residues. The N- and C-lobes, each including a 5-strand beta-sheet, are coloured in blue and pink, respectively. Loops are represented as grey lines, with white circles indicating their length (number of residues). The five motifs conserved both in MOB_T and Rep_trans proteins are boxed in dotted rectangles. In addition, the motif N″ conserved in MOB_T proteins identified in this work is also boxed. The residues mutated in this work are indicated and coloured as follows: yellow for residues chelating the divalent cation, blue for the catalytic conserved tyrosine, green for other conserved residues. b. Front view of the homology 3-D model of RelSt3 core-domain. Beta-strands are coloured as in Fig. 4a. Helices and loops are in green. Important residues of the active site are represented as sticks and coloured as in Fig. 4a. c side view of the 3-D RelSt3 model, illustrating the crescent-shaped structure with the active site in the centre. The yellow ball indicates the probable location of the divalent cofactor, according to the model