A number of enzymes, belonging to the lyase class, for which fumarate is a
substrate have been shown [1,2] to share a short conserved sequence around a
methionine which is probably involved in the catalytic activity of this type
of enzymes. These enzymes are:
Fumarase (EC 220.127.116.11) (fumarate hydratase), which catalyzes the reversible
hydration of fumarate to L-malate. There seem to be 2 classes of fumarases:
class I are thermolabile dimeric enzymes (as for example: Escherichia coli
fumC); class II enzymes are thermostable and tetrameric and are found in
prokaryotes (as for example: Escherichia coli fumA and fumB) as well as in
eukaryotes. The sequence of the two classes of fumarases are not closely
Aspartate ammonia-lyase (EC 18.104.22.168) (aspartase), which catalyzes the
reversible conversion of aspartate to fumarate and ammonia. This reaction
is analogous to that catalyzed by fumarase, except that ammonia rather than
water is involved in the trans-elimination reaction.
Arginosuccinase (EC 22.214.171.124) (argininosuccinate lyase), which catalyzes the
formation of arginine and fumarate from argininosuccinate, the last step in
the biosynthesis of arginine.
Adenylosuccinase (EC 126.96.36.199) (adenylosuccinate lyase) , which catalyzes
the eight step in the de novo biosynthesis of purines, the formation of
5'-phosphoribosyl-5-amino-4-imidazolecarboxamide and fumarate from 1-(5-
phosphoribosyl)-4-(N-succino-carboxamide). That enzyme can also catalyzes
the formation of fumarate and AMP from adenylosuccinate.
Pseudomonas putida 3-carboxy-cis,cis-muconate cycloisomerase (EC 188.8.131.52)
(3-carboxymuconate lactonizing enzyme) (gene pcaB) , an enzyme involved
in aromatic acids catabolism.
December 2004 / Pattern and text revised.
PROSITE method (with tools and information) covered by this documentation:
Woods S.A. Schwartzbach S.D. Guest J.R.
Two biochemically distinct classes of fumarase in Escherichia coli.
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