Figure 1.

(A) Schematic illustration of the A. fumigatus HapX domain organization. The N-terminal Hap4-like CBC binding domain (CBC-BD) is shown in blue. Basic region and coiled coil parts of the bZIP domain are depicted in red and green, respectively. Cysteine-rich regions are marked in yellow. Cysteine-rich regions A and B are essential for HapX function during iron excess but not during iron starvation, while the C-terminus is crucial during iron starvation (shown in turquois). Residues N65, Q69, F72 and R73, which mediate specific DNA contacts in the Schizosaccharomyces pombe bZIP Pap1:DNA complex (17), are labeled with a black triangle. The location of a putative monopartite nuclear localization sequence (NLS) motif identified within the Aspergillus oryzae HapX basic region (18) is shown in grey.