A Unique Promoter Architecture Defines Menin-KMT2A Complex Selectivity

Selective occupancy of chromatin-regulatory complexes is central to developmental gene regulation, yet the sequence determinants of this selectivity remain poorly understood. Using interpretable machine learning, we identify a composite promoter architecture comprising CpG islands flanked by several-kilobase A/T-rich domains (AT-flanks) that denotes high occupancy of the Menin-KMT2A histone-modifying complex at developmental and leukemia-associated genes. Genetic deletion and chromatin-contact analyses show that AT-flanks support KMT2A retention at linked CpG islands. We identify LEDGF as an A/T-rich DNA-associated protein required for Menin engagement at AT-flanks and sustained KMT2A promoter occupancy. AT-flank extent is associated with differential KMT2A loss following pharmacologic disruption of the Menin-KMT2A interaction, providing a genomic basis for heterogeneous target sensitivity to recently approved Menin inhibitors in acute leukemia. Beyond Menin-KMT2A, the same architecture distinguishes promoters with high canonical PRC1 occupancy across diverse cell types, revealing a shared sequence organization associated with distinct chromatin-regulatory states.