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PROSITE documentation PDOC00925

Iodothyronine deiodinases active site


Iodothyronine deiodinase (EC (DI) [1,2] is the vertebrate enzyme responsible for the deiodination of the prohormone thyroxine (T4 or 3,5,3',5'-tetraiodothyronine) into the biologically active hormone T3 (3,5,3'-triiodothyronine) and of T3 into the inactive metabolite T2 (3,3'-diiodothyronine). Three types of DI are known. All known DI are proteins of about 250 residues that contain a selenocysteine at their active site.

As a signature pattern we selected the best conserved region, it is located in the central part of the enzyme and contains the active site selenocysteine.

Last update:

January 2008 / Pattern updated.

Technical section

PROSITE method (with tools and information) covered by this documentation:

T4_DEIODINASE, PS01205; Iodothyronine deiodinases active site  (PATTERN)


1AuthorsSt Germain D.L.
Source(In) Thyroid hormone metabolism: molecular biology and alternative pathways, Wu S.Y., Visser T.J., Eds., pp45-66, CRC Press, Ann Arbor, (1994).

2AuthorsDavey J.C., Becker K.B., Schneider M.J., St Germain D.L., Galton V.A.
TitleCloning of a cDNA for the type II iodothyronine deiodinase.
SourceJ. Biol. Chem. 270:26786-26789(1995).
PubMed ID7592917

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