Binding of potential regulatory proteins of H. jecorina to the AGAA-box within the xyn2 promoter. First, 100 μg cell-free extracts derived from replacement experiments on glucose and xylan were subjected to an EMSA. Then, 10 ng of the radioactive-labelled oligonucleotides Pxyn2a (covering the area in the xyn2 promoter harbouring the AGAA-box (grey box; antisense strand), see Table 1) and Pxyn2aM (bearing a mutation of AGAA to CTCC (M), see Table 1) were used. Free probe indicates the sample lacking protein. Xyr1 indicates the Xyr1-binding sites (black boxes; GGGTAA on the sense strand and GGCTGG on the antisense strand). CCAAT indicates the binding site of the Hap2/3/5 complex (white box: antisense strand).