title: Papaya proteinase IV amino acid sequence.
abstract: The amino acid sequence of papaya proteinase IV (PPIV), a major proteinase from the latex of Carica papaya [(1989) Biochem. J. 261, 469-476] is described. The enzyme has a high degree of sequence identity with papaya proteinase III, chymopapain and papain (81, 70 and 67%, respectively), and is clearly a member of the papain superfamily of cysteine proteinases. Nevertheless, the sequence shows substitution of certain residues conserved in all other known members of the superfamily. It is suggested that some of these substitutions may account for the unusual specificity of PPIV.
authors.affiliation: Department of Biochemistry, J. Stefan Institute, Ljubljana, Yugoslavia.
authors.forename: A
authors.initials: A
authors.lastname: Ritonja
authors.forename: D J
authors.initials: DJ
authors.lastname: Buttle
authors.forename: N D
authors.initials: ND
authors.lastname: Rawlings
authors.forename: V
authors.initials: V
authors.lastname: Turk
authors.forename: A J
authors.initials: AJ
authors.lastname: Barrett
mesh_terms: D000595:Amino Acid Sequence; D003546:Cysteine Endopeptidases / Q000032:analysis / Q000235:genetics*; D005638:Fruit / Q000201:enzymology*; D008969:Molecular Sequence Data
chemical_list: D003546:Cysteine Endopeptidases; C050874:glycyl endopeptidase