Sequence-independent 6mA methyltransferases for epigenetic profiling and editing.

Gene activity is intricately shaped by its chromatin environment. Deciphering the chromatin landscape is essential for understanding the complex regulatory networks governing gene function. The newly re-recognized DNA N⁶-methyladenine (6mA) is relatively scarce in multicellular eukaryotes, which has facilitated the development of innovative chromatin profiling approaches employing sequence-independent 6mA methyltransferases (MTases) to introduce exogenous 6mA. In this review, we summarize recent advances in leveraging exogenous 6mA deposition and long-read sequencing in three major applications: chromatin landscape profiling, protein-DNA interaction mapping, and targeted epigenetic editing. For each, we outline representative workflows, highlight technical advantages, and discuss current challenges and prospects for optimization. Together, this review underscores the emerging power of exogenous 6mA as a versatile tool for decoding chromatin architecture and gene regulation.