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* Thiamine pyrophosphate enzymes signature *
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A number of enzymes  require  thiamine  pyrophosphate  (TPP) (vitamin B1) as a
cofactor.  It has been shown [1] that  some  of these enzymes are structurally
related. These related TPP enzymes are:

 - Pyruvate oxidase (POX) (EC 1.2.3.3)
   Reaction catalyzed: pyruvate + orthophosphate + O(2) + H(2)O = acetyl
   phosphate + CO(2) + H(2)O(2).
 - Pyruvate decarboxylase (PDC) (EC 4.1.1.1)
   Reaction catalyzed: pyruvate = acetaldehyde + CO(2).
 - Indolepyruvate decarboxylase (EC 4.1.1.74) [2]
   Reaction catalyzed: indole-3-pyruvate = indole-3-acetaldehyde + CO(2).
 - Acetolactate synthase (ALS) (EC 4.1.3.18)
   Reaction catalyzed: 2 pyruvate = acetolactate + CO(2).
 - Benzoylformate decarboxylase (BFD) (EC 4.1.1.7) [3]
   Reaction catalyzed: benzoylformate = benzaldehyde + CO(2).

As  a signature pattern for these enzymes we  have selected a conserved region
which is located in their C-terminal section.

-Consensus pattern: [LIVMF]-[GSA]-x(5)-P-x(4)-[LIVMF]-x-[LIVMF]-x-G-D-[GSA](2)
-Sequences known to belong to this class detected by the pattern: ALL,  except
 for Hanseniaspora uvarum and maize PDC.
-Other sequence(s) detected in SWISS-PROT: a hypothetical  protein in the  puf
 phothosynthesis operon of Rhodobacter capsulatus; this protein could be a TPP
 enzyme.

-Note: other TPP enzymes  such as the E1  component of pyruvate  dehydrogenase
 complex, 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate  synthase, and
 transketolase do not seem to be related to the above enzymes.

-Last update: June 1994 / Text revised.

[ 1] Green J.B.A.
     FEBS Lett. 246:1-5(1989).
[ 2] Koga J., Adachi T., Hidaka H.
     Mol. Gen. Genet. 226:10-16(1991).
[ 3] Tsou A.Y., Ransom S.C., Gerlt J.A., Buechter D.D., Babbitt P.C.,
     Kenyon G.L.
     Biochemistry 29:9856-9862(1990).