CLK β7-β8 hairpin insert and anchoring residues. Comparison of the residue interactions anchoring the β-hairpin insert to the kinase C-lobe in solved structures of PfLAMMER [PDB:3LLT] and human Clk2 [PDB:3NR9]. (A) Both structures superimposed, with corresponding key residues shown in "sticks" representation. The contrastingly conserved residue (from CHAIN analysis) is highlighted cyan: D653 in PfLAMMER, Q266 in human Clk2. A residue of interest near the base of the hairpin insert, discussed in the text, is shown in yellow; its type is not strongly conserved within apicomplexan CLKs. Two residues in the loop of the hairpin, colored green, are inserts in PfLAMMER relative to Clk2; they appear anchored to the kinase C-lobe by interactions with a lysine, dark blue. (B) Human Clk2, showing side chains near the residues of interest. A hydrogen bond appears between the αE-helix glutamine (cyan) and the backbone of a valine (yellow) near the base of the hairpin insert. (C) In PfLAMMER, the two residues of interest, D653 (cyan) and T711 (yellow), do not interact directly; each instead forms several novel hydrogen bonds with other nearby residues, shown in green and blue, corresponding to those shown in green and gray in the human Clk2 structure.
Talevich et al. BMC Evolutionary Biology 2011 11:321 doi:10.1186/1471-2148-11-321