Member database | PROSITE patterns |
PROSITE patterns type | conserved site |
Short name | AA_TRANSFER_CLASS_4 |
Description
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] 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.
References
1.Characterization and sequence of Escherichia coli pabC, the gene encoding aminodeoxychorismate lyase, a pyridoxal phosphate-containing enzyme. Green JM, Merkel WK, Nichols BP. J. Bacteriol. 174, 5317-23, (1992). View articlePMID: 1644759