MALIC ENZYME FAMILY: STRUCTURAL-BIOCHEMICAL ANALYSIS TO IMPROVES CATALYTIC PROPERTIES

SAIGO MARIANA; ARIAS C.L.,; ALVAREZ CLARISA ESTER; GERRARD WHEELER M.C.; ALEJANDRA MUSSI, MARÍA; MAURINO V.G.

Congreso; LVII Reunión Anual de SAIB y el XVI Congreso Anual de la Asociación Civil de Microbiología General (SAMIGE); 2021

Structure-function studies contribute to deciphering how small modifications in the primary structure could introduce desirable characteristics into enzymes without affecting its overall functioning. Malic enzymes (ME) are ubiquitous and participate in different biological functions as diverse as lipogenesis, photosynthesis and organic acid metabolism. In the presence of a divalent cation, this enzyme catalyzes the oxidative decarboxylation of malate to pyruvate, NAD(P)H, and CO2. MEs of several sources including humans, pigeons, nematodes, bacteria, phytopathogens and plants have been kinetically and structurally characterized. Our results, which combine structural, biochemical, phylogenetic and functional analysis, show that this family have members with: different structural conformation (like homo/hetero-dimers, tetramers, oligomers, bifunctional enzymes), post-traductional modifications and specie-specific regulation. In relation to this, we recently gained novel information provided by the crystal structural analysis of the photosynthetic ME of maize and sorghum, and of the minimal functional ME structure known until now, from Candidatus Phytoplasma mali. Currently, we started applying all the knowledge obtained to perform rational design modification of two groups of enzymes: i. the bifunctional MEs, which have high potential to produce new generation of biofertilizers; and ii. the photosynthetic ME isoform, that is a key candidate to improve crop yields. By these strategies, we try to improve photosynthetic efficiency of agronomic crops that has not reached their maximum potential and will not be enough to feed the world´s population in the near future.