(B) 3Q, 5Q, 3A, 5A, 2A and Δ506-515 mutants of hCAP-H. Motif IV (residues 461-503) contains amino-acid residues highly conserved among eukaryotic species (X, Xenopus laevis; Dr, Danio rerio; Cm, Cyanidioschyzon merolae; Sp, Schyzosaccharomyces pombe; Sc, Saccharomyces cerevisiae; Ec, Encephalitozoon cuniculi). To produce the IV-3Q, 5Q, 3A, 5A and 2A mutants, the conserved aromatic amino-acid residues (F463, F469, F473, F501 and Y503; labeled in dark blue) were substituted with glutamine (Q) or alanine (A) residues. The secondary structural element of hCAP-H is drawn below the sequence alignments. 