Indoleamine 2,3-dioxygenase (EC 1.13.11.42) (IDO) [1] is an enzyme responsible
for the conversion of tryptophan and other indole derivatives to kynurenines.
In mammals, IDO is induced by interferon-γ (IFN-γ) and responsible for
some of its anti-proliferative effects. The degradative action of IDO on
tryptophan leads to cell death by starvation of this essential and relatively
scarce amino acid. IDO is a heme-containing enzyme of about 400 amino acids.
Other proteins that are evolutionarily related to IDO are:
- Myoglobin from the red muscle of the gastropods Nordotis madaka and
Sulculus diversicolor [2]. These unusual globins lack enzymatic activity
but have kept the heme group.
- Yeast hypothetical protein YJR078w.
As a signature for the IDO family, we selected two conserved regions. The
first is located in the central section and is rich in glycine and serine
residues; the second is located in the second third of the sequence and
contains a conserved histidine that could serve as a proximal ligand to the
heme iron.
PROSITE is copyright. It is produced by the Swiss Institute of
Bioinformatics (SIB). 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 license@isb-sib.ch or
see: http://www.expasy.org/prosite/prosite_license.htm.
ExPASy Home page
SIB Switzerland