Crystal structure of human NADK2 reveals a dimeric organization and active site occlusion by lysine acetylation.

ABSTRACT: NAD⁺ kinases (NADKs) are metabolite kinases that phosphorylate NAD⁺ molecules to make NADP⁺, a limiting substrate for the generation of reducing power NADPH. NADK2 sustains mitochondrial NADPH production that enables proline biosynthesis and antioxidant defense. However, its molecular architecture and mechanistic regulation remain undescribed. Here, we report the crystal structure of human NADK2, revealing a substrate-driven mode of activation. We find that NADK2 presents an unexpected dimeric organization instead of the typical tetrameric assemblage observed for other NADKs. A specific extended segment (aa 325-365) is crucial for NADK2 dimerization and activity. Moreover, we characterize numerous acetylation events, including those on Lys76 and Lys304, whi

SUBMITTER: Mary C 

PROVIDER: S-EPMC10353453 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature