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- ******************************************
- * Indoleamine 2,3-dioxygenase signatures *
- ******************************************
-
- Indoleamine 2,3-dioxygenase (EC 1.13.11.42) (IDO) [1] is an enzyme which is
- responsible for the conversion of tryptophan and other indole derivatives to
- kynurenines. In mammals IDO is induced by interferon-gamma (IFN-gamma) and is
- 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.
-
- The red muscle of the gastropod Sulculus contains an unusual myoglobin which
- is evolutionarily related to IDO [2]; this protein lacks enzymatic activity
- but has kept its heme group.
-
- 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 pattern 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.
-
- -Consensus pattern: G-G-S-A-[GA]-Q-S-S-x(2)-Q
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Consensus pattern: Y-M-x-P-A-H-[KR]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Last update: October 1993 / First entry.
-
- [ 1] Taylor M.W., Feng G.S.
- FASEB J. 5:2516-2522(1991).
- [ 2] Suzuki T., Takagi T.
- J. Mol. Biol. 228:698-700(1992).
-