Schematic representation of the MLL, p300, and putative MLL-p300 chimeric proteins. The functional domains of MLL and p300 are shown beneath the figure. The nt and single-letter amino acid sequences surrounding the MLL-p300 breakpoint are shown at the bottom of the figure. NLS, nuclear localization signal; C/H, cysteine/histidine-rich region; Q rich, glutamine-rich region; ZF, Zinc finger domain; CREB, CREB-binding site; E1A, E1A binding site. Arrows indicate the breakpoint of each gene and the fusion point of chimeric protein. MLL-p300 fusion junction is in-frame, and putative chimeric protein loses part of the C/H-rich region and the CREB-binding site located in p300.