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* Malic enzymes signature *
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Malic enzymes  (malate oxidoreductase)  catalyze the oxidative decarboxylation
of malate into pyruvate, a reaction important  for  a  wide range of metabolic
pathways. There are two related forms of malic enzyme:

 - NADP-dependent  malic  enzyme  (EC  1.1.1.40)  [1,2],  found in animals and
   plants. In  mammals,  there  are two isozymes: one, mitochondrial, which is
   more effective  with  NAD  then NADP  and the other, cytosolic. Plants also
   have two isozymes,  chloroplastic and cytosolic.
 - NAD-dependent malic enzyme (EC 1.1.1.38) [3], found in bacteria.

There are three other proteins structurally closely related to malic enzymes:

 - A plant enzyme  previously  thought to be  a cinnamyl-alcohol dehydrogenase
   (CAD) [4], but which is probably a malic enzyme.
 - Escherichia coli protein sfcA, whose  function  is not yet known  but which
   could be a NAD or NADP-dependent malic enzyme.
 - Yeast hypothetical protein YKL029c, a probable malic enzyme.

There are  three  well  conserved regions in the enzyme sequences. Two of them
seem to be involved in binding NAD or NADP. The significance of the third one,
located in the central part of the enzymes, is not yet known. We have selected
this region as a signature pattern for these enzymes.

-Consensus pattern: F-x-D-D-x(2)-G-T-[GA]-x-V-x(2)-[GAST](2)-[LIVM](2)
-Sequences known to belong to this class detected by the pattern: ALL.
-Other sequence(s) detected in SWISS-PROT: NONE.

-Expert(s) to contact by email: Glynias M.
                                mglynias@ncsa.uiuc.edu

-Last update: June 1994 / Pattern and text revised.

[ 1] Rothermel B.A., Nelson T.
     J. Biol. Chem. 264:19587-19592(1989).
[ 2] Loeber G., Infante A.A., Maurer-Fogy I., Krystek E., Dworkin M.B.
     J. Biol. Chem. 266:3016-3021(1991).
[ 3] Kobayashi K., Doi S., Negoro S., Urabe I., Okada H.
     J. Biol. Chem. 264:3200-3205(1989).
[ 4] Walter M.H., Grima-Pettenati J., Grand C., Boudet A.M., Lamb C.J.
     Plant Mol. Biol. 15:525-526(1990).