title: Rice aspartic proteinase, oryzasin, expressed during seed ripening and germination, has a gene organization distinct from those of animal and microbial aspartic proteinases.
abstract: The gene organization and nucleotide sequence of an aspartic proteinase (AP) of plant origin were first disclosed by cDNA and genomic DNA cloning of a rice AP (oryzasin). The deduced amino acid sequence of oryzasin 1 was significantly similar to those of other APs (34-85%), with highest similarity (85%) to barley AP (HvAP). Oryzasin 1, as well as HvAP, is distinct from animal and microbial APs in that the plant APs contain a unique 104-amino-acid insertion in the C-terminal region. The oryzasin 1 gene spans approximately 6.6 kbp and is composed of 14 exons and 13 introns. The exon-intron organization of the oryzasin 1 gene is totally different from those of genes for animal and microbial APs such as human cathepsin D, rat renin, bovine chymosin, aspergillopepsin A of Aspergillus awamori, proteinase A of Saccharomyces cerevisiae and rhizopuspepsin of Rhizopus niveus, despite the fact that oryzasin 1 shows overall sequence similarity to these APs.
authors.affiliation: Laboratory for Food Science, Atomi Junior College, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Asakura
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
authors.forename: K
authors.initials: K
authors.lastname: Abe
authors.forename: S
authors.initials: S
authors.lastname: Arai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000096:biosynthesis* / Q000235:genetics*; D001483:Base Sequence; D002417:Cattle; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D018525:Germination; D006801:Humans; D008969:Molecular Sequence Data; D012275:Oryza / Q000201:enzymology*; D051381:Rats; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary; D016282:Aspartic Acid Endopeptidases; C105394:oryzasin