| Type: | Family | Name: | Cereal allergen/alpha-amylase inhibitor, rice-type |
| Description: | Seeds of cereals contain a variety of serine protease and alpha-amylase inhibitors. These inhibitors can be grouped into families based on structural similarities. Rice seed allergenic proteins (RA) have sequence homology to seed trypsin/alpha-amylase inhibitors. Some have serine peptidase activity or alpha-amylase, and a few are bifunctional. The proteins contain ~10 cysteine residues, all of which are involved in disulphide bond formation [].This majority of sequences in this family are from Oryza sativa(Rice), exceptions are from Hordeum vulgare(Barley) and Triticum aestivum(Wheat). The majority are annotated either as alpha-amylase inhibitors or seed allergens and all belong to the MEROPS inhibitor family I6, clan IJ. There is no direct evidence to suggest that they can inhibit serine peptidases belonging to MEROPS peptidase S1 [], and studies on a closely related alpha-amylase inhibitor from Secale cereale(Rye) demonstrates no activity against trypsin, and illustrates the necessity of exercising caution in assigning function based on sequence comparisons [].The rice seed allergenic proteins are encoded by a multigene family consisting of at least four members. A conserved sequence similar to a motif identified in rice glutelin promoters was observed in the 5' region of the two genes. RA genes are specifically expressed in ripening seeds and they accumulate maximally 15-20 days after flowering []. | Short Name: | Allergen/amylase_inhib_rice |
