Description
Neisseria gonorrhoeae, the causative agent of gonorrhea, poses a growing global health threat due to the rapid emergence of antimicrobial resistance (AMR). Novel therapeutic strategies are urgently needed to combat this pathogen. Nucleoside diphosphate kinase (NDPK) from N. gonorrhoeae (NgNDPK) represents a promising drug target because it catalyzes a key step in the nucleotide salvage pathway, which is essential for bacterial survival. NDPKs maintain cellular nucleotide homeostasis by transferring γ-phosphate groups from nucleoside triphosphates to diphosphates via a phospho-histidine intermediate. Despite previous characterization in model organisms, the structural and functional features of NDPKs from pathogenic bacteria remain poorly understood. Here, we report the structural and biochemical characterization of NgNDPK. The crystal structure reveals a tetrameric assembly, with each subunit adopting the canonical α/β-sandwich fold composed of a central four-stranded antiparallel β-sheet (β1-β4) flanked by α-helices. In contrast, human NDPKs typically form hexamers. Sequence analysis identified key differences between NgNDPK and human NDPK isoforms, particularly within the catalytic kpn-motif involved in substrate binding and phosphoryl transfer. These findings provide new insight into the architecture and potential regulatory mechanisms of NgNDPK and establish a foundation for structure-guided inhibitor design targeting this essential enzyme in N. gonorrhoeae.