9xyw

Crystal structure of the maize chloroplastic non-photosynthetic NADP(+)-dependent malic enzyme

spinqualitylabelsall models 9xyw, resolution 2.55Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 9xyw is a 2 chain structure with sequence from Zea mays. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.55Å Ligands: FMT, MG, NAP, PYR Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function A0A4Y2_MAIZE Publication Abstract from PubMed NADP-dependent malic enzyme (NADP-ME) has been repeatedly co-opted into distinct metabolic roles across plants, most prominently as the decarboxylase of NADP-ME-type C4 photosynthesis. In maize, the plastidic C4- and nonC4-NADP-ME isoforms are closely related in sequence yet display strikingly different catalytic properties, suggesting that small changes in ligand recognition can re-tune reaction chemistry. However, mechanistic interpretation has been hampered by the scarcity of plant NADP-ME structures captured in catalytically informative, ligand-bound states. Here, we integrate X-ray crystallography with structure-guided docking and atomistic molecular dynamics (MD) to resolve ligand-site interaction networks across reaction states. We determined a 2.55 A structure of maize plastidic nonC4-NADP-ME bound to NADP(+), pyruvate, and Mg(2+), revealing a conserved NADP-ME fold with localized active-site flexibility. Comparison with maize C4-NADP-ME uncovers isoform-specific rewiring of NADP(+) and pyruvate contacts, with the nonC4 enzyme forming a denser product-cofactor interaction network. To access substrate-bound states, we reconstructed malate-NADP(+)-Mg(2+) complexes by docking followed by MD, identifying distinct malate-Mg(2+) coordination geometries and alternative NADP(+) positioning between isoforms. Together, these structures and simulations provide a network-level framework for plastidic NADP-ME functional diversification and generate testable hypotheses for how ligand coordination drives isoform-specific catalysis. Integrative crystallography and molecular dynamics reveal isoform-specific ligand interaction networks in C4 and nonC4 plant NADP-malic enzyme.,Bohm JM, Klinke S, Zamarreno F, Schneberger N, Lunari R, Saigo M, Drincovich MF, Willms S, Costabel M, Maurino VG, Alvarez CE Plant J. 2026 Aug;127(3):e71064. doi: 10.1111/tpj.71064. PMID:42531153 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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