Homology modeling involves taking a known sequence with an unknown structure and mapping it against a known structure of one or several similar (homologous) proteins. It would be expected that two proteins of similar origin and function would have reasonable structural similarity. Therefore it is possible to use the known structure as a template for modeling the structure of the unknown structure. Proteins that share the same function generally have similar structures. During alignment if two proteins show maximum sequence identity they also show a similar folding pattern. This principal has became the foundation of homology modeling. 
The Geminivirus taxonomic group of plant viruses is characterized by geminate particles and genomes consisting of single-stranded circular DNA molecules of about 2.5 to 2.8 kb in size. Agricultural plants are threatened by many diseases caused by whitefly-transmitted geminiviruses. Since these diseases are in a fast spreading phase, it is urgent to devise rapid diagnosis methods and to produce resistant plants. 

