PROSITE documentation PDOC51700
SEPARIN core domain profile


In eukaryotic cells, replicated DNA strands remain physically connected until their segregation to opposite poles of the cell during anaphase. This "sister chromatid cohesion" is essential for the alignment of chromosomes on the mitotic spindle during metaphase. Cohesion depends on the multisubunit cohesin complex, which possibly forms the physical bridges connecting sisters. The separins (separases) cleave the Scc1p subunit of the cohesin complex, allowing the separation of sister chromatids in anaphase. Separins are highly conserved in all eukaryotes but have not been detected in prokaryotes [1,2].

All known separin homologs possess a conserved C-terminal "separin" domain. The separin core domain contains a conserved histidine and cyteine residue, which are hallmarks of cysteine proteases. These two residues are invariably surrounded by small residues (glycine or serine), and each is preceded by amino acid sequences that are predicted to form hydrophobic β sheets. This pattern is characteristic of cysteine endopeptidases of the CD clan [E1], which includes caspases, legumains, gingipains, clostripains, anf GPI-anchor amidases. The histidine end cysteine residues are likely to form the separin domain's catalytic dyad [1,2]. The separin core domain forms the peptidase C50 family [E2].

The profile we developed covers the entire SEPARIN core domain.

Last update:

January 2014 / First entry.


Technical section

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

SEPARIN, PS51700; SEPARIN core domain profile  (MATRIX)


1AuthorsUhlmann F. Wernic D. Poupart M.-A. Koonin E.V. Nasmyth K.
TitleCleavage of cohesin by the CD clan protease separin triggers anaphase in yeast.
SourceCell 103:375-386(2000).
PubMed ID11081625

2AuthorsAravind L. Koonin E.V.
TitleClassification of the caspase-hemoglobinase fold: detection of new families and implications for the origin of the eukaryotic separins.
SourceProteins 46:355-367(2002).
PubMed ID11835511


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