PROSITE documentation PDOC00299
Microbodies C-terminal targeting signal


Microbodies are a class of small, single membraned organelles to which belong peroxisomes, glyoxysomes, and glycosomes. Microbody proteins are synthesized on free polysomes and imported into the organelle post-translationally. Unlike the import of proteins into mitochondria, chloroplasts or the ER/secretion pathway, import into microbodies does not generally require the removal of a presequence [1]. It has been experimentally shown [2,3,4] that, in some peroxisomal proteins, the targeting signal (PTS) resides in the last three amino acids of the C-terminus. This consensus sequence is known as 'S-K-L' (Ser-Lys-Leu), although some variations are allowed in all three positions. As the peroxisomal targeting signal also seems to be recognized by other microbodies, it is now [1] known as the C-terminal microbody targeting signal (CMTS).

It must be noted that not all microbody proteins contain a CMTS; some seem to contain an internal CMTS-like sequence, but it is not yet known if it is active as such. Finally, a few proteins are synthesized with an N-terminal presequence which is cleaved off during import.

Microbody proteins known or thought to contain a CMTS are listed below.

  • Mammalian D-amino acid oxidase.
  • Mammalian acyl-coenzyme A oxidase (but not the fungal enzymes).
  • Mammalian and yeast (S. cerevisiae) carnitine o-acetyltransferase.
  • Mammalian trifunctional fatty acid β oxidation pathway enzyme.
  • Mammalian, insect, plants, and Aspergillus uricase.
  • Mammalian sterol carrier protein-2 high molecular form (SCP-X).
  • Mammalian long chain α-hydroxy acid oxidase.
  • Mammalian soluble epoxide hydrolase (sEH).
  • Firefly luciferase.
  • Plants glycolate oxidase.
  • Plants glyoxisomal isocitrate lyase.
  • Plants and fungal glyoxisomal malate synthase.
  • Trypanosoma glycosomal glucose-6-phosphate isomerase.
  • Trypanosoma glycosomal glyceraldehyde 3-phosphate dehydrogenase.
  • Yeast (H. polymorpha and Pichia pastoris) alcohol oxidase (AOX).
  • Yeast (H. polymorpha) dihydroxy-acetone synthase (DHAS).
  • Yeast (S. cerevisiae) catalase A.
  • Yeast (S. cerevisiae) citrate synthase.
  • Yeast (S. cerevisiae) peroxisomal malate dehydrogenase.
  • Yeast (C. boidinii) peroxisomal protein PMP20.
  • Yeast (C. tropicalis) hydratase-dehydrogenase-epimerase (HDE) from fatty acid β oxidation pathway.
  • Yeast (C. tropicalis) isocitrate lyase.
  • Aspergillus niger monoamine oxidase N.
  • Candida albicans vacuolar aspartic protease PRA1.
Last update:

November 1997 / Pattern and text revised.


Technical section

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

MICROBODIES_CTER, PS00342; Microbodies C-terminal targeting signal  (PATTERN with a high probability of occurrence!)


1AuthorsDe Hoop M.J. Ab G.
SourceBiochem. J. 286:657-669(1992).

2AuthorsGould S.J. Keller G.-A. Subramani S.
TitleIdentification of peroxisomal targeting signals located at the carboxy terminus of four peroxisomal proteins.
SourceJ. Cell Biol. 107:897-905(1988).
PubMed ID2901422

3AuthorsGould S.J. Keller G.-A. Hosken N. Wilkinson J. Subramani S.
TitleA conserved tripeptide sorts proteins to peroxisomes.
SourceJ. Cell Biol. 108:1657-1664(1989).
PubMed ID2654139

4AuthorsGould S.J. Keller G.-A. Schneider M. Howell S.H. Garrard L.J. Goodman J.M. Distel B. Tabak H. Subramani S.
TitlePeroxisomal protein import is conserved between yeast, plants, insects and mammals.
SourceEMBO J. 9:85-90(1990).
PubMed ID2104803

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