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-III, currently consists of the following enzymes:
Acetylornithine aminotransferase (EC 220.127.116.11) which catalyzes the transfer
of an amino group from acetylornithine to α-ketoglutarate, yielding
N-acetyl-glutamic-5-semi-aldehyde and glutamic acid.
Ornithine aminotransferase (EC 18.104.22.168), which catalyzes the transfer of
an amino group from ornithine to α-ketoglutarate, yielding glutamic-5-
semi-aldehyde and glutamic acid.
Omega-amino acid--pyruvate aminotransferase (EC 22.214.171.124), which catalyzes
transamination between a variety of omega-amino acids, mono- and diamines,
and pyruvate. It plays a pivotal role in omega amino acids metabolism.
4-aminobutyrate aminotransferase (EC 126.96.36.199) (GABA transaminase), which
catalyzes the transfer of an amino group from GABA to α-ketoglutarate,
yielding succinate semialdehyde and glutamic acid.
DAPA aminotransferase (EC 188.8.131.52), a bacterial enzyme (gene bioA) which
catalyzes an intermediate step in the biosynthesis of biotin, the
transamination of 7-keto-8-aminopelargonic acid (7-KAP) to form 7,8-
diaminopelargonic acid (DAPA).
2,2-dialkylglycine decarboxylase (EC 184.108.40.206), a Pseudomonas cepacia
enzyme (gene dgdA) that catalyzes the decarboxylating amino transfer of
2,2-dialkylglycine and pyruvate to dialkyl ketone, alanine and carbon
Glutamate-1-semialdehyde aminotransferase (EC 220.127.116.11) (GSA). GSA is the
enzyme involved in the second step of porphyrin biosynthesis, via the C5
pathway. It transfers the amino group on carbon 2 of glutamate-1-
semialdehyde to the neighbouring carbon, to give delta-aminolevulinic acid.
Bacillus subtilis aminotransferase yhxA.
Bacillus subtilis aminotransferase yodT.
Haemophilus influenzae aminotransferase HI0949.
Caenorhabditis elegans aminotransferase T01B11.2.
The sequence around the pyridoxal-phosphate attachment site of this class of
enzyme is sufficiently conserved to allow the creation of a specific pattern.
December 2004 / Pattern and text revised.
PROSITE method (with tools and information) covered by this documentation:
Unpublished observations (1992).
Yonaha K., Nishie M., Aibara S.
J. Biol. Chem. 267:12506-12510(1992).
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