ME1:Mg2+ tetramer oxidatively decarboxylates MAL to PYR

Stable Identifier
Reaction [transition]
Homo sapiens
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One hallmark of cancer is altered cellular metabolism. Malic enzymes (MEs) are a family of homotetrameric enzymes that catalyse the reversible oxidative decarboxylation of L-malate to pyruvate, with a simultaneous reduction of NAD(P)+ to NAD(P)H. As MEs generate NADPH and NADH, they may play roles in energy production and reductive biosynthesis. Humans possess three ME isoforms; ME1 is cytosolic and utilises NADP+, ME3 is mitochondrial and can utilise NADP+ and ME2 is mitochondrial and can utililse either NAD+ or NADP+ (Chang & Tong 2003, Murugan & Hung 2012).

NADP-dependent malic enzyme (ME1, aka c-NADP-ME) is a cytosolic enzyme that oxidatively decarboxylates (s)-malate (MAL) to pyruvate (PYR) and CO2 using NADP+ as cofactor (Zelewski & Swierczynski 1991). ME1 exists as a dimer of dimers (Murugan & Hung 2012, Hsieh et al. 2014) and a divalent metal such as Mg2+ is essential for catalysis (Chang & Tong 2003).

Literature References
PubMed ID Title Journal Year
14596586 Structure and function of malic enzymes, a new class of oxidative decarboxylases

Tong, L, Chang, GG

Biochemistry 2003
23284632 Biophysical characterization of the dimer and tetramer interface interactions of the human cytosolic malic enzyme

Murugan, S, Hung, HC

PLoS ONE 2012
1935931 Malic enzyme in human liver. Intracellular distribution, purification and properties of cytosolic isozyme

Zelewski, M, SwierczyƄski, J

Eur. J. Biochem. 1991
24998673 Structural characteristics of the nonallosteric human cytosolic malic enzyme

Li, SY, Chen, HY, Hung, HC, Yang, PC, Hsieh, JY, Chen, MC, Chan, NL, Liu, JH

Biochim. Biophys. Acta 2014
Catalyst Activity

malate dehydrogenase (decarboxylating) (NADP+) activity of ME1:Mg2+ tetramer [cytosol]

Orthologous Events
Cross References
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