Fig. 5: Mutating specificity determinant residues identified using FIKK13 D379N structure allows for changes in FIKK substrate specificity.

a, Overlay of FIKK13 D379N kinase domain crystal structure with ATPƔS (grey) and the FIKK13 kinase domain AlphaFold structure prediction coloured according to the residues pLDDT score. The r.m.s.d. was calculated using PyMol¹¹⁵. b, A target peptide (EKKASEGDN) of FIKK12 was modelled into the substrate-binding groove of the FIKK12 AlphaFold structure (Methods). The K212 and K263 kinase residues are predicted to bind to the peptide at the +1 and +3 positions. K212 is found on the large β1–β2 loop that is N-terminal to the first β-strand on the kinase N-lobe. Boundaries of the β1–β2 loop lies between residues 202 and 217 (inclusive). K263 is found on the loop between the αB and αC helices (boundaries between residues 257 and 267 (inclusive)). Secondary structure regions are referred to (for reference) in Extended Data Figs. 6 and 10. The sequence logos show the residue conservation between FIKK12 Plasmodium sequences (top), and basophilic Plasmodium sequences (bottom). The FIKK12 kinase domain is coloured according to the pLDDT score, the same as for a. c, FIKK12 WT and FIKK12 mutants phosphorylation activity on OPAL membranes represented as heat maps (see Fig. 3a(i) caption). Below is represented the PWM logos (see Fig. 3a(ii) caption).