**2.3 Protein structure prediction**

The field of structural biology is mostly dominated by experimental methods which are expensive and laborious in nature. However, since the last few decades, the application of computational techniques in structural biology has been widely used, with significant improvements in these techniques since last 10–20 years. This has helped to achieve substantial developments in protein structure prediction methods. *In-silico* protein structure prediction enables the prediction of 3D structures for proteins with known sequences and unknown structures. Prediction of the tertiary structure also helps in understanding the folding and unfolding of proteins. Also, protein engineering may help in incorporation of new functions in proteins thus facilitating drug design and discovery [15]. Protein structure prediction can be achieved by three different ways:

