B-DNA minor groove

The B-DNA minor groove is a distinct structural feature of the B-form DNA double helix, characterized by a narrow and relatively shallow path between the sugar-phosphate backbones. It serves as a critical site for the binding of various regulatory proteins, including transcription factors and polymerases, which are essential for gene expression, DNA replication, and repair (1, 2). In pharmacology, the minor groove is a primary target for minor groove binders (MGBs), a class of small molecules that typically exhibit high affinity for specific nucleotide sequences, most commonly AT-rich regions (3). These interactions can displace essential proteins, inhibit enzymatic processes such as topoisomerase activity, or, in the case of covalent binders like pyrrolobenzodiazepines, cause irreversible DNA damage (4). Consequently, the B-DNA minor groove is a significant target in the development of therapies for cancer, as well as bacterial, viral, and parasitic infections (5). However, the therapeutic use of minor groove-targeting agents is often complicated by challenges such as systemic toxicity, genotoxicity, and the difficulty of achieving high sequence specificity to avoid off-target effects in healthy cells (3, 4).

Other names

DNA minor grooveB-form DNA minor grooveMinor groove of B-DNA

Drugs targeting the B-DNA minor groove primarily act as minor groove binders (MGBs) that occupy the groove through non-covalent interactions such as hydrogen bonding, van der Waals forces, and electrostatic attraction (1). This binding often occurs at AT-rich sequences where the groove is narrowest and the negative electrostatic potential is highest, effectively displacing water molecules and stabilizing the DNA structure (2). By occupying the groove, these agents competitively inhibit the binding of essential DNA-interacting proteins, including transcription factors and topoisomerases, thereby halting transcription and replication (3). Additionally, certain MGBs like pyrrolobenzodiazepines (PBDs) or nitrogen mustards can form covalent adducts with the exocyclic amino groups of bases, leading to DNA cross-linking and potent cytotoxicity (4, 5).