Malate dehydrogenase (decarboxylating)

NAD-malic enzyme
Identifiers
EC number 1.1.1.39
CAS number 9028-46-0
Databases
IntEnz IntEnz view
BRENDA BRENDA entry
ExPASy NiceZyme view
KEGG KEGG entry
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum
Gene Ontology AmiGO / EGO

Malate dehydrogenase (decarboxylating) (EC 1.1.1.39) or NAD-malic enzyme (NAD-ME) is an enzyme that catalyzes the chemical reaction

(S)-malate + NADP+ \rightleftharpoons pyruvate + CO2 + NADPH

Thus, the two substrates of this enzyme are (S)-malate and NAD+, whereas its three products are pyruvate, CO2, and NADH. Malate is oxidized to pyruvate and CO2, and NAD+ is reduced to NADH.

This enzyme belongs to the family of oxidoreductases, to be specific, those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is (S)-malate:NAD+ oxidoreductase (decarboxylating). This enzyme participates in pyruvate metabolism and carbon fixation. NAD-malic enzyme is one of three decarboxylation enzymes used in the inorganic carbon concentrating mechanisms of C4 and CAM plants. The others are NADP-malic enzyme and PEP carboxykinase.[1][2]

Structural studies

As of late 2007, 7 structures have been solved for this class of enzymes, with PDB accession codes 1DO8, 1EFK, 1EFL, 1PJ2, 1PJ3, 1PJ4, and 1QR6.

References

  1. Kanai R, Edwards, GE (1999). "3. The Biochemistry of C4 Photosynthesis". In Sage RF, Monson RK. C4 Plant Biology. pp. 43–87. ISBN 0126144400.
  2. Christopher JT, Holtum JAM (1996). "Patterns of carbon partitioning in leaves of Crassulacean acid metabolism species during deacidification". Plant Physiol. 112 (1): 393–399. doi:10.1104/pp.112.1.393. PMC 157961. PMID 12226397.