Summary for clan SJ

Summary Alignment Structure Literature
Clan type peptidaseS16.001 - Lon-A peptidase (Escherichia coli), MEROPS Accession MER0000485 (peptidase unit: 537-784); PDB accession 1RR9_A
HistoryMEROPS 6.6 (27 March 2004)
DescriptionSerine nucleophile; catalytic residues in the order Ser, Lys in sequence
Contents of clanClan SJ contains endopeptidases.
EvidenceThe inclusion of family S50 within the clan is based on similar sequence motifs around the active site residues, Gly-Gln-Ser-Ala-Xaa-Xbb and Lys-Xbb-Xbb-Ala-Ala-His, where Xaa is a small amino acid and Xbb is an aliphatic hydrophobic residue (Birghan et al., 2000; see the Alignment).
Catalytic mechanismThere is a Ser, Lys catalytic dyad. The catalytic mechanism in family S16 has been discussed by Botos et al. (2004).
Peptidase activityThe enzymes are endopeptidases (see families S16 and S50).
Protein foldTertiary structures have only been determined for members of family S16 (endopeptidase La, S16.001; Botos et al., 2004). Endopeptidase La is an alpha/beta protein in which the secondary structure elements are in two layers, each with a beta sheet and helices. The active site lies between the layers.
Homologous non-peptidase familiesThe fold is similar to that of a number of nucleic acid-binding proteins, including DNA gyrase, ribonucleases P and PH, elongation factors G and 2, ribosomal proteins S5 and S9 and enzymes such as UDP-3-O-[3-hydroxymyristoyl] N-acetylglucosamine deacetylase LpxC and imidazole glycerol phosphate dehydratase (see SCOP sunid 54211).
Other databases SCOP54211

Families

Family Family Type Inhibitor Structure
S16 Lon-A peptidase (Escherichia coli) Yes
S50 infectious pancreatic necrosis birnavirus Vp4 peptidase (infectious pancreatic necrosis virus) Yes
S69 Tellina virus 1 VP4 peptidase (Tellina virus 1) Yes

Distribution of clan SJ among Kingdoms of Organisms

FamilyBacteriaArchaeaProtozoaFungiPlantsAnimalsViruses
S16+++++++
S50+-----+
S69------+
Clan+++++++