Abstract
This paper presents an
in silico
characterization of the chitin binding protein CBP50 from
B. thuringiensis
serovar konkukian S4
through homology modeling and molecular docking. The CBP50 has shown a modular structure containing an N-terminal
CBM33 domain, two consecutive fibronectin-III (Fn-III) like domains and a C-terminal CBM5 domain. The protein presented a
unique modular structure which could not be modeled using ordinary procedures. So, domain wise modeling using
MODELLER and docking analyses using Autodock Vina were performed. The best conformation for each domain was selected
using standard procedure. It was revealed that four amino acid residues Glu-71, Ser-74, Glu-76 and Gln-90 from N-terminal
domain are involved in protein-substrate interaction. Similarly, amino acid residues Trp-20, Asn-21, Ser-23 and Val-30 of Fn-III
like domains and Glu-15, Ala-17, Ser-18 and Leu-35 of C-terminal domain were involved in substrate binding. Site-directed
mutagenesis of these proposed amino acid residues in future will elucidate the key amino acids involved in chitin binding
activity of CBP50 protein.