ID   7.2.4.4
DE   biotin-dependent malonate decarboxylase.
AN   malonate carboxy-lyase (biotin-dependent).
AN   malonate decarboxylase.
CA   H(+) + malonate + Na(+)(in) = acetate + CO2 + Na(+)(out).
CC   -!- Two types of malonate decarboxylase are currently known, both of
CC       which form multienzyme complexes.
CC   -!- The enzyme described here is a membrane-bound biotin-dependent,
CC       Na(+)-translocating enzyme.
CC   -!- The other type is a biotin-independent cytosolic protein (cf.
CC       EC 4.1.1.88).
CC   -!- As free malonate is chemically rather inert, it has to be activated
CC       prior to decarboxylation.
CC   -!- Both enzymes achieve this by exchanging malonate with an acetyl group
CC       bound to an acyl-carrier protiein (ACP), to form malonyl-ACP and
CC       acetate, with subsequent decarboxylation regenerating the acetyl-
CC       bound form of the enzyme.
CC   -!- The ACP subunit of both enzymes differs from that found in fatty-acid
CC       biosynthesis by having phosphopantethine attached to a serine side-
CC       chain as 2-(5-triphosphoribosyl)-3-dephospho-CoA rather than as
CC       phosphopantetheine 4'-phosphate.
CC   -!- In the anaerobic bacterium Malonomonas rubra, the components of the
CC       multienzyme complex/enzymes involved in carrying out the reactions of
CC       this enzyme are as follows: MadA (EC 2.3.1.187), MadB (EC 7.2.4.1),
CC       MadC/MadD (EC 2.1.3.10) and MadH (EC 6.2.1.35).
CC   -!- Two other components that are involved are MadE, the acyl-carrier
CC       protein and MadF, the biotin protein.
CC   -!- The carboxy group is lost with retention of configuration.
CC   -!- Formerly EC 4.1.1.89.
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