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  into subfamilies. One of these,
called class-II, currently consists of the following enzymes:
Glycine C-acetyltransferase (EC 220.127.116.11), which catalyzes the addition of
acetyl-CoA to glycine to form 2-amino-3-oxobutanoate (gene kbl).
5-aminolevulinic acid synthase (EC 18.104.22.168) (delta-ALA synthase), which
catalyzes the first step in heme biosynthesis via the Shemin (or C4)
pathway, i.e. the addition of succinyl-CoA to glycine to form 5-
8-amino-7-oxononanoate synthase (EC 22.214.171.124) (7-KAP synthase), a bacterial
enzyme (gene bioF) which catalyzes an intermediate step in the biosynthesis
of biotin: the addition of 6-carboxy-hexanoyl-CoA to alanine to form 8-
Histidinol-phosphate aminotransferase (EC 126.96.36.199), which catalyzes the
eighth step in histidine biosynthetic pathway: the transfer of an amino
group from 3-(imidazol-4-yl)-2-oxopropyl phosphate to glutamic acid to form
histidinol phosphate and 2-oxoglutarate.
Serine C-palmitoyltransferase (EC 188.8.131.52) from yeast (genes LCB1 and
LCB2), which catalyzes the condensation of palmitoyl-CoA and serine to form
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Unpublished observations (1991).
PROSITE is copyright. It is produced by the SIB Swiss Institute
Bioinformatics. There are no restrictions on its use by non-profit
institutions as long as its content is in no way modified. Usage by and
for commercial entities requires a license agreement. For information
about the licensing scheme send an email to
or see: prosite_license.html.