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{PDOC00098}
{PS00105; AA_TRANSFER_CLASS_1}
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* Aminotransferases class-I pyridoxal-phosphate attachment site *
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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-I, currently consists of the following enzymes:

 - Aspartate aminotransferase (AAT) (EC 2.6.1.1). AAT catalyzes the reversible
   transfer of  the  amino  group  from  L-aspartate to 2-oxoglutarate to form
   oxaloacetate and  L-glutamate.  In  eukaryotes, there are two AAT isozymes:
   one is  located  in the mitochondrial matrix, the second is cytoplasmic. In
   prokaryotes, only one form of AAT is found (gene aspC).
 - Tyrosine  aminotransferase  (EC  2.6.1.5) which catalyzes the first step in
   tyrosine catabolism  by  reversibly  transferring  its  amino  group  to 2-
   oxoglutarate to form 4-hydroxyphenylpyruvate and L-glutamate.
 - Aromatic  aminotransferase  (EC 2.6.1.57) involved in the synthesis of Phe,
   Tyr, Asp and Leu (gene tyrB).
 - 1-aminocyclopropane-1-carboxylate  synthase   (EC 4.4.1.14)  (ACC synthase)
   from plants.   ACC   synthase   catalyzes   the   first  step  in  ethylene
   biosynthesis.
 - Pseudomonas   denitrificans   cobC,   which   is   involved   in  cobalamin
   biosynthesis.
 - Yeast hypothetical protein YJL060w.

The sequence around the pyridoxal-phosphate  attachment site  of this class of
enzyme is sufficiently conserved to allow the creation of a specific pattern.

-Consensus pattern: [GS]-[LIVMFYTAC]-[GSTA]-K-x(2)-[GSALVN]-[LIVMFA]-x-[GNAR]-
                    {V}-R-[LIVMA]-[GA]
                    [K is the pyridoxal-P attachment site]
-Sequences known to belong to this class detected by the pattern: ALL.
-Other sequence(s) detected in Swiss-Prot: 1.
-Last update: April 2006 / Pattern revised.

[ 1] Bairoch A.
     Unpublished observations (1992).
[ 2] Sung M.H., Tanizawa K., Tanaka H., Kuramitsu S., Kagamiyama H.,
     Hirotsu K., Okamoto A., Higuchi T., Soda K.
     "Thermostable aspartate aminotransferase from a thermophilic Bacillus
     species. Gene cloning, sequence determination, and preliminary x-ray
     characterization."
     J. Biol. Chem. 266:2567-2572(1991).
     PubMed=1990006;

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