{PDOC00618}
{PS00770; AA_TRANSFER_CLASS_4}
{BEGIN}
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* Aminotransferases class-IV signature *
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Aminotransferases  share certain mechanistic features with   other  pyridoxal-
phosphate dependent enzymes, such as  the  covalent  binding of the pyridoxal-
phosphate group  to  a  lysine  residue.  On the basis of sequence similarity,
these various  enzymes  can  be  grouped [1,2] into subfamilies. One of these,
called class-IV, currently consists of the following enzymes:

 - Branched-chain amino-acid aminotransferase  (EC 2.6.1.42) (transaminase B),
   a bacterial   (gene   ilvE)  and  eukaryotic  enzyme  which  catalyzes  the
   reversible transfer  of  an  amino  group  from 4-methyl-2-oxopentanoate to
   glutamate, to form leucine and 2-oxoglutarate.
 - D-alanine   aminotransferase   (EC  2.6.1.21).  A  bacterial  enzyme  which
   catalyzes the transfer of the amino group from D-alanine (and other D-amino
   acids) to 2-oxoglutarate, to form pyruvate and D-aspartate.
 - 4-amino-4-deoxychorismate (ADC) lyase (gene pabC). A  bacterial enzyme that
   converts ADC into 4-aminobenzoate (PABA) and pyruvate.

The above enzymes  are  proteins of about 270  to 415 amino-acid residues that
share a few regions of sequence similarity.  Surprisingly, the  best conserved
region does not include the  lysine residue  to  which the pyridoxal-phosphate
group is  known  to  be  attached,  in  ilvE. The region we use as a signature
pattern is located some 40 residues at the C-terminus side of the PlP-lysine.

-Consensus pattern: E-x-[STAGCI]-x(2)-N-[LIVMFAC]-[FY]-x(6,12)-[LIVMFA]-x-T-
                    x(6,8)-[LIVM]-x-[GS]-[LIVM]-x-[KR]
-Sequences known to belong to this class detected by the pattern: ALL.
-Other sequence(s) detected in Swiss-Prot: 1.
-Last update: December 2001 / Pattern and text revised.

[ 1] Green J.M., Merkel W.K., Nichols B.P.
     "Characterization and sequence of Escherichia coli pabC, the gene
     encoding aminodeoxychorismate lyase, a pyridoxal phosphate-containing
     enzyme."
     J. Bacteriol. 174:5317-5323(1992).
     PubMed=1644759
[ 2] Bairoch A.
     Unpublished observations (1992).

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