Carboxypeptidase_S10

Family: Carboxypeptidase_S10

Block: X

Parent Family: No family

Comment

Serine carboxypeptidase-like (SCPL) proteins. Structures determined for wheat and yeast peptidase first. Very successful family in plants (arabdopsis) also human protective protein cathepsineA. The protective protein human-CTSA is a glycoprotein that associates with lysosomal beta-galactosidase and neuraminidase and is deficient in the autosomal recessive disorder Galactosialidosis . Also contains non peptidase sequences as hydroxynitril lyase from plants. But new structure of sorghum hnl shows clear differences in catalytic mechanism because of a deletion of two amino acid adjescent of the active site serine: see sorbi-hnl and 1GXS Lauble et al 2002. It does not accept aliphatic hydroxynitriles, unlike EC 4.1.2.10 mandelonitrile lyase and EC 4.1.2.39 hydroxynitrilase. Other hydroxynitril lyase belong to another family: Hydroxynitrile_lyase . This Carboxypeptidase family also contains acyltransferases as sinapoyltransferase AT2G22990 arath-SCP8 SNG1 gene. Another enzyme, related to the SCPL family, is glucose acyltransferase from Lycopersicon pennellii catalysing the formation of diacylglucose. Some of these SCPL have a T instead of the serine in the catalytic triad: probably no catalytic activity but partner of another Serine carboxypeptitase-like protein.