BIOINFORMATICS ANALYSIS USING HOMOLOGY MODELING TO PREDICT THE THREE-DIMENSIONAL STRUCTURE OF Spodoptera littoralis (Lepidoptera: Noctuidae) AMINOPEPTIDASE N RECEPTOR

Insect pests are the major cause of damage to commercially important agricultural crops. The continuous application of synthetic pesticides resulted in developing severe insect resistance in addition to induce irreversible damage to the environment. Bacillus thuringiensis (Bt) emerged as a valuable biological alternative in pest control. The midgut aminopeptidase N (APN) of pest insect is a receptor for Bacillus thuringiensis Cry1 toxin. A 108.58 kDa APN has been characterized in Spodoptera littoralis. In the present in silico study, a homology model of SlAPN was constructed using Swiss-Model,  Protein  Modeling  Server. The study detected that SlAPN three-dimensional structure has 4 structural domains. Domain I of the receptor is the region that recognizes Cry1 toxins, a part of this section might be very important in this role. Domain II has functions in Cry1 protein-APN interaction. Domain III has a sandwich topology and domain IV is a superhelix. The present data help in the development of a roadmap for the design and synthesis of novel Cry toxins and improve toxic activities depending on the APN's conserved structures which will contribute to the management of insect resistance in the field.