Sedolisins (serine-carboxyl peptidases) are proteolytic enzymes whose fold ressembles that of subtilisin; however they are considerably larger, with the mature catalytic domains containing approximately 375 amino acids. The defining features of these enzymes are a unique catalytic triad, Ser-Glu-Asp (SED in single-letter notation), as well as the presence of an aspartic acid residue in the oxyanion hole. Sedolisins are acid-acting endopeptidases or tripeptidyl peptidases. They are widely distributed among archea, bacteria, fungi, slime mold, amoeba and animal kingdom including amphibians, fish and mammals. Sedolisins form peptidase family S53 of the subtilisin-like (SB) clan [1,2,3,E1].

The three dimensional fold of sedolisin is based on a 7-stranded, all-parallel β-sheet. The sheet is flanked on both sides by several helices (see <PDB:1GA6>) [1].

Some proteins known to contain a sedolisin domain are listed below:

• Pseudomonas sedolisin.
• Xanthomonas sp. Xanthomonalisin.
• Bacterial kumamolisin.
• Aspergillus oryzae aorsin.
• Fungal sedolisin-B, a secreted tripeptidyl-peptidase which degrades proteins at acidic pHs and is involved in virulence.
• Mammalian lysosomal tripeptidyl-peptidase 1 (TPP-1) or CLN2, involved in hydrolysis of hydrophobic proteins. A hereditary deficiency of human TPP-1 results in infantile neuronal ceroid lipofuscinosis (Batten disease), a rare but fatal neurodegenerative disorder.

The profile we developed covers the entire sedolisin domain.