Molecular Cloning & Homology Modeling of Lectin Gene With Mannose Binding Protein From Garlic (Allium Sativum L.)

Abstract

One of the most important direct defense responses in plants against the attack by phytophagous insects is the production of insecticidal peptides or proteins known as lectins. There is no Bacillus thuringiensis (Bt) toxin available which is effective against hemipteran . insects. Plant lectins have been shown to be toxic to some insects, including sucking paste, aphids, in particular lectins from garlic. Structural studies have demonstrated that the mannosebinding specificity of lectins is mediated by distinct structural scaffolds. Thus, in the present study attempt was made to clone Allium sativum L. lectin gene and homology based structure prediction of lectin gene. A 1033 bp DNA fragment was amplified .using modified primers Lee 1 F & Lee R designed from the lectin sequences of Allium sativum L. The amplicons were cloned in to a cloning vector pTZ57RJT and transformed into E. coli DH5a.. The pCAMBIA plasmid was prepared by the restriction digestion by removing gus region. The restricted gene was then ligated in prepared plasmid and then subjected to clone into E. coli DH5a.. The band of 1033 bp was showing positive result in colony PCR. The lectin sequence from garlic was then used to comparative modeling of lectin. Some software's and online tools were used for this purpose. The 3D structure of lectin was prepared. The model of lectin protein described about their length 98 amino acids with mannose binding sites. The comparative modeling of lectin gene may be helpful in the understanding about structure and function of similar proteins. It can be concluded that some insecticidallectins are useful tools that can contribute to the development of integrated pest management strategies with minimal effects on non-target organisms. So there is needed to make transgeni~ crops containing lectin to fulfill the requirement of increasing world's population.